GOSWAMI, C. J.:- This appeal is directed against an order of the learned Subordinate Judge passed on 18-5-1964 whereby he set aside a sale under O. 21, R. 90, Civil P. C., holding that the judg­ment-debtor suffered great loss and sub­stantial injury "due to material irregu­larity in proclaiming the attachment of the property and in proclaiming the sale of the same." 2. The decree-holder who was the auc­tion purchaser is the appellant before us. The respondent-judgment-debtor examin­ed six witnesses before the Court below including himself by commission. The decree-holder examined eight witnesses on his behalf. The learned Subordinate Judge held that the attachment was irregular and invalid as no copy of the attachment "was served in the Court house and in the office of the Collector. He further held that there was material ir­regularity in not publishing the sale by beat, of drum or any such customary manner and for not serving any copy in the Court house. He also held that there was non-compliance of the provisions of Order 21, Rule 68, Civil P. C. in holding the sale on 6th April 1959 within thirty days of 10th March, 1959, the date of af­fixing the copy of the sale proclamation on the Court house at Mangaldai, although the sale was ordered by the Subordinate Judge at Gauhati. The learned Subor­dinate Judge, after noting the above as material irregularities, dealt with the question whether any substantial injury was caused to the judgment-debtor on ac­count of the said sale and held in his favour. 3. The facts briefly are that the decree-holder had a decree against the judgment-debtor for a sum of Rs. 41,000 and odd, in execution of which he prayed for sale of the judgment-debtor's immovable pro­perty situated at Kharupatia in Mangaldai sub-division. The Subordinate Judge at Gauhati, who passed the sale order, en­trusted the Munsiff at Mangaldai for con­ducting the sale. The judgment-debtor was served with the writ of attachment as well as the notice for settlement of terms of sale proclamation; together with a copy of the proclamation of sale, as is clear from his endorsements in his own hand-vide Exts. A(l), B(l) and C(l). The judgment-debtor for the first time ap­peared in Court on 7-9-1957 praying for stay of execution till the disposal of his appeal in the Supreme Court against the decree. A(l), B(l) and C(l). The judgment-debtor for the first time ap­peared in Court on 7-9-1957 praying for stay of execution till the disposal of his appeal in the Supreme Court against the decree. He is therefore, in the know of the execution proceedings and was repre­sented by a lawyer in the same. The judgment-debtor's main objections are that the attachment effected under Order 21, Rule 54. Civil P. C. is irregular; that the proclamation did not contain a proper description of the property and that the sale took place on 6-4-1959 before the expiry of thirty days from the date of affixing a copy of the sale proclamation on the Court house, assuming that the Court of the Munsiff is the proper Court for the purpose although the judgment-debtor submits that the appropriate Court was the Court of the Subordinate Judge where no copy of the sale proclamation has been affixed. The sale commenced before the Munsiff on 6th April 1959 and continued on 7th, 8th, llth, 13th and 16th April 1959, on which date one Sitaram (D, W. 8) offered a bid of Rs. 33000/- on behalf of the decree-holder and the sale was knocked down in his favour as the highest bidder. The sale report from Munsiff, Mangaldai was received by the Subordinate Judge at Gauhati on 20th April 1959 and the judgment-debtor made an application under Order 21, Rule 90, Civil P. C. on 22nd April 1959 for setting aside the sale. 4. On the questions of law raised in this appeal, it is necessary to see whether there was any substantial injury which resulted from the sale in question to the judgment debtor on account of any material irregularity. At this stage, we may read O. 21, R. 90. Civil P. C.. 4. On the questions of law raised in this appeal, it is necessary to see whether there was any substantial injury which resulted from the sale in question to the judgment debtor on account of any material irregularity. At this stage, we may read O. 21, R. 90. Civil P. C.. as tanended in Assam: "Where any immovable property has been sold in execution of a decree, the decree-holder, or any person entitled to share in a rateable distribution of assets, or whose interests are affected by the sale, may apply to the Court to set aside the sale on the ground of a material ir­regularity or fraud in publishing or con­ducting it or on the ground of failure to issue notice to him as required by R. 22 of this Order: Provided (i) that no sale shall be set aside on the ground of such irregularity, fraud or failure unless, upon the facts proved, the Court is satisfied that the ap­plicant has sustained substantial injury by. reason of such irregularity, fraud or failure. (ii) That no sale shall be set aside on the ground of any defect in the proclama­tion of sale at the instance of any person who after notice did not attend at the drawing up of the proclamation or of any person in whose presence the proclama­tion was drawn up, unless objection was made by him at the time in respect of the defect relied upon." It is therefore, clear that the scope of Rule 90 is that the sale may be set aside on the ground of material irregularity if the Court is satisfied upon the facts prov­ed before it that the applicant has sustain­ed substantial injury by reason of the material irregularity found. We are not re­quired to consider the other grounds men­tioned in Rule 90 in the instant case. The question will therefore, arise whether there has been any material irregularity in publishing or conducting the sale. The sale, as is- well known, is preceded by a proclamation under O. 21, Rule 66 and Order 21. Rule 67 prescribes the mode of making a proclamation and the manner is as prescribed by Order 21, Rule 54 as in the case of attachment. The sale, as is- well known, is preceded by a proclamation under O. 21, Rule 66 and Order 21. Rule 67 prescribes the mode of making a proclamation and the manner is as prescribed by Order 21, Rule 54 as in the case of attachment. , Order-21, Rule 68 may be read, omitting what is- not neces­sary for the purpose of this case:- "Time of sale:- X X X X X ...............no sale hereunder shall, with­out the consent in writing of the judg­ment-debtor, take place until after the expiration of at least thirty days in the case of immoveable property ...............calculated from the date on which the copy of the proclamation has been affixed, on the court-house of the Judge ordering the sale." Order 21, Rule 69 refers to adjournment or stoppage of sale. The above are the material provisions which need to be con­sidered in deciding the controversy raised in this .appeal. 5. It is clear that in an application under Rule 90 it will not be open to -the judgment-debtor to question that there was some irregularity regarding attach­ment of the property. Besides, in this case, the judgment-debtor having been served with a copy of the writ of attach­ment is estopped from questioning this as he, by his own endorsement in the writ of attachment, has waived his right to object on the score of irregularity of attachment. Regarding the terms of sale proclamation also the judgment-debtor must be held to have waived his rights to object to any misdescription of property in the sale proclamation. The judgment-debtor in absence of substantial injury cannot be heard to say that the sale, on account of those irregularities complained of, is a nullity and that the Court had no jurisdiction to continue the sale of the property. The question, however, will be different when the judgment-debtor com­plains substantial injury resulting from these material irregularities which, al­though will not make the sale a nullity, will subject it to close scrutiny to find out whether it has resulted in any sub­stantial injury to the judgment-debtor as in this case. The terms of Order 21,1 Rule 68 are indeed imperative, but even so a sale that takes place without comply-: ing with these provisions may not per se be null and void. Mr. The terms of Order 21,1 Rule 68 are indeed imperative, but even so a sale that takes place without comply-: ing with these provisions may not per se be null and void. Mr. S. C. Choudhury, the learned coun­sel for the respondent, drew our attention to a decision of the Nagpur High Court in AIR 1954 Nag 240 (Kisan Dinaji v. Deorao Nathuji) wherein it has been held that the terms of Rule 68 are imperative and the sale held before the expiration of thirty days from the date of the publication of the sale proclamation is vitiated. With all respect, although we are in agreement with the above decision so far as the terms of Rule 68 are concerned that these are imperative, yet we are unable to agree that the sale is vitiated on that score. It does not appear that the learned single Judge's attention in that case was drawn to a decision of the Privy Council in the Law Reports 20 Irid App 176 (PC) (Tassaduk Rasul Khan v. Ahmad Husain) -a decision dated 24th June 1893, where the Privy Council had to consider the ef­fect of Section 290 of the Old Civil P. C. (Act 14 of 1882) which corresponds to the new provisions of Order 21, Rule 68, Civil P. C. The Privy Council held that non-compliance of Section 290 is a material irregularity within the meaning of Sec­tion 311, but a sale in disregard of Sec­tion 290 is not a nullity and will not be set aside unless direct evidence of sub­stantial injury resulting from the irregu­larity has been given. To a similar effect the Supreme Court has recently observed in AIR 1964 SC 1300 (Dhirendra Nath Gorai v. Sudhir Chandra Ghosh). Their Lordships were considering a case from the Calcutta High Court under Order 21, Rule 90, Civil'P. C. read with Section 35 of the Bengal Money Lenders Act. Sec­tion 35 has got provisions 6f the nature of those under Order 21, Rule 66(2) (a), Civil P. C. and their Lordships have ob­served as follows:- "It Is not correct to say that the sale held in contravention of the provisions of Section 35 of the Act was a nullity and therefore, no question of setting aside the sale within the meaning of O. 21, R. 90, Civil P. C. would arise. The safest rule to determine what is an irregularity and what is nullity is to see whether the party can waive the objection; if he can waive it, it amounts to an irregularity: if hg cannot, it is a nullity." 6. At this stage, it may be useful, to passing, to notice the fine distinction be­tween irregularity and nullity and it is not possible to improve upon a workable test laid down by Coleridge, J. in Holmes v. Russell, (1841) 9 Dowl 487 to the follow­ing effect:- "It Is difficult sometimes to distinguish between an irregularity and a nullity; but the safest rule to determine what is an Irregularity and what is a nullity is to see whether the party can waive the objec­tion; if he can waive it, it amounts- to an Irregularity; if he cannot, it is a nullity." As Maxwell "on the Interpretation of Statutes", (llth Edition, page 375) puts it: "Everyone has a right to waive and to agree to waive the advantage of a law or rule made solely for the benefit and pro­tection of the individual in his private capacity, which may be dispensed with without infringing any public right or public policy." To a similar effect has Craies on Statute Law (6th Edition, page 269) observed: "...............if it appears that the statu­tory conditions were inserted by the legis­lature simply for the security or benefit of the parties to the action themselves, and that no public interests are involved, such conditions will not be considered as indis­pensable, and either party may waive them without affecting the jurisdiction of the Court." It is therefore, clear that a party cannot by waiver confer jurisdiction on a Court lacking it, but even a mandatory provision can be waived if it is not intended in the in­terests of the public and only conceived In the interests of the party that waives. 7. The judgment-debtor In this case has clearly waived his right to object to the sale proclamation on the ground of mistake in description of the property, but he cannot be said to have waived the thirty days requirement of Order 21 Rule 68. He was not present when the sale notice was affixed on the Court house of the Munsiff. None was affixed on the Court house of the Subordinate Judge who had ordered the sale. He was not present when the sale notice was affixed on the Court house of the Munsiff. None was affixed on the Court house of the Subordinate Judge who had ordered the sale. The second proviso to Rule 90 relates only to defect in the sale proclamation. The defect pointed out in this case, relating to non-compliance of Order 21, Rule 68, is not covered by the second proviso to Rule 90. Even, generally speaking, the judgment-debtor in this case has not waived his right to question the sale on the score of violation of Order 21, Rule 68. 8. The provision of Order 21, Rule 68 clearly provides a terminus a quo which Is the date on which the copy of the pro­clamation has been affixed on the Court house of the Judge ordering the sale and the period of thirty days has to be cal­culated from this date which is very material. This express provision has only to be contrasted with the absence of it in Order 21, Rule 54 in order to appreciate the imperative character of the provisions of Rule 68. Any violation of this would be a clear material irregularity in the pro­cess of publication of the sale. in the instant case. The sale having commenced within thirty days but continuing for a period more than that and having been concluded without that period will not make the sale itself a nullity, but it is certainly a material irregularity within the meaning of Rule 90(1). 9. The material Irregularity being there, the next point to be considered is whether this material irregularity has resulted in any substantial injury to the judgment-debtor. The learned Subordi­nate Judge, after examining the evidence of the witnesses on both sides, appears to come to the conclusion that the judgment-debtor's property worth about Rupees 1,00,000/- had been sold at a lower value of Rs. 33,0007- to the decree-holder. The judgment-debtor has produced several witnesses P. Ws. 2, 3 and 4 who deposed by exhibiting their deeds of conveyance of land in the locality (Exts. 3, 4 and 5). The decree-holder also produced a wit­ness (D. W. 7) who has proved his re­gistered sale deed Ext. F. The learned counsel for the judgment-debtor has pointed out that the average market value of the land alone, which may be struck from these sale deeds, comes to about Rs. 4498/- per bigha. 3, 4 and 5). The decree-holder also produced a wit­ness (D. W. 7) who has proved his re­gistered sale deed Ext. F. The learned counsel for the judgment-debtor has pointed out that the average market value of the land alone, which may be struck from these sale deeds, comes to about Rs. 4498/- per bigha. Besides this, there are permanent structures on the land which have been valued by a retired Surveyor of Local Board (P. W. 5) at Rs. 91.735/-. This valuation by the Surveyor has, of course, been made at the instance of the judgment-debtor and may even be ex­aggerated. At any rate, we are satisfied that the entire property which measures more than twelve bighas of land with house property on it cannot be less than Rs. 1,00,000/- and the learned Subordinate Judge is not unjustified on the evidence on record when he put the figure even at Rs. 1,20,000/-. The learned Subordinate Judge has also referred to a security bond, Ext. 1, which was accepted by the Court on the report of the Sheristadar (P. W. 1) who deposed to the effect that the value of the property, which is now the subject-matter of these proceedings, was worth more than Rs. 1,00,000/-, vide Ext. 2. This security bond was given when there was an order tot attachment before judgment in the Original Suit and the plaintiff-decree-holder did not object to the valua­tion of the property at that stage. We, therefore, agree that the valuation of the property as given by the learned Subordinate Judge and the property sold would be of the value of more than Rs. 1,00,000/-. The learned counsel for the decree-holder, at one stage, drew our attention to the fact that because of a diversion' of public road the property in question was not at that time on the main road. This would, however, not affect the value of this property in a bazar. The value of the property is not, because of the situs of the land but because of the commercial value being a bazar site, howsoever inconvenient it may be from other points of view. 10. We have now to see whether there is any substantial injury which has resulted on account of this material irre­gularity. The property situated in a bazar area, although at Kharupatia, is of commercial value to merchants and trad­ers even elsewhere. 10. We have now to see whether there is any substantial injury which has resulted on account of this material irre­gularity. The property situated in a bazar area, although at Kharupatia, is of commercial value to merchants and trad­ers even elsewhere. The decree-holder himself is a businessman of Gauhati and spread his business to that place which must be therefore of some importance. If the property were advertised at the Court of the Subordinate Judge at Gauhati who had ordered the sale, it was likely to have attracted rival bidders from a wider area. The absence of publication at Gauhati would lead to black out the sale where it should have been more widely circulated. Although the sale was con­tinuing for about six days, there were no bidders on three intervening dates on 8th, 9th and llth April. There were only two bidders on 13th including the decree-holder and on the final date 16th April,, there were two bidders including the decree-holder and the sale was knock­ed down in his favour at Rs. 33,000/-. This would also show that non-publica­tion of the sale proclamation on the court house at Gauhati must have affect­ed the bidding and the resultant sale. It Is because of this reason that the decree-holder was able to have the property at a lower value of Rs. 33,000/-. We are, therefore, satisfied that the judgment-debtor has sustained substantial injury by reason of the material irregularity pointed out and the sale has been rightly set aside by the learned Subordinate Judge. 11. The appeal is dismissed, but we will make no order as to costs. 12. D. JM. SEN. J.:. I agree. Appeal dismissed.