This appeal has been filed by assesssee against order dated 11- 11-1983 of Commissioner passed under section 263 of Income-tax Act, 1961 ('the Act') for assessment year 1978-79 2. By this order, Commissioner has set aside entire assessment n d directed assessing officer to make fresh assessment after giving proper opportunities of hearing to assessee. assessing officer in this case was IAC who has made assessment under section 143(3) of Act on 19-11-1981. 3. Shri P. T. Sanyal, learned representative for assessee, took us through first of 10 grounds taken in this appeal which reads as below: "That order under section 263 passed by learned Commissioner of Income-tax, in respect of assessment order dated 19-11-1981 is bad and without jurisdiction since said assessment order was passed by Inspecting Assistant Commissioner of Income-tax and not by Income-tax Officer." Shri P. T. Sanyal urged before us that Commissioner did not have any jurisdiction to revise sunder section 263 order passed by IAC, According to him said jurisdiction of Commissioner is confined to orders passed by ITO only. He referred to Explanation to section 263(1) introduced by section 47 of Taxation Laws (Amendment) Act, 1984, with effect from 1-10- 1984 and so it was not available for supporting order of commissioner which was passed on 11-11-1981. He contended that there was doubt prior to introduction of aforesaid Explanation and so Legislature has removed that doubt with effect from particular date and not before that date. Consequently, doubt which existed prior to that date has to be resolved in favour of assessee in view of decision of Supreme Court in case of CIT v. Vegetable Products Ltd. (1973) 88 ITR 192. 4. Shri G. P. Nanda, learned representative for department, on other hand, supported order of Commissioner. He stated that this point has been considered by Commissioner in his order dated 11-11-1983. Commissioner has stated that section 125A (4) of Act stipulates that where IAC exercises functions of ITO, any reference, in Act or Income-tax Rules, 1962 ('the Rules') to ITO shall be construed as reference to IAC. Further, he stated that aforesaid Explanation was clarificatory legislation and it has declared law as it has always been right from beginning. mention of date 1-10-1984 from which said Explanation came into effect in his opinion makes no difference to above basic position. He referred to decision in case of CIT v. Bejoy Kumar Almal (1977) 106 ITR 743 (Cal.) in this connection. In that case it was held that where provision is enacted for express purpose of explaining or clearing up issues as to meaning of previous enactment, such Explanation should normally govern earlier Act. Such Explanation is confined to subject-matter of prior enactment and presumption is that it is retrospective. That case was dealing with Explanation to section 26 of Act. It may be mentioned that said Explanation did not state that law contained therein was being declared for removal of doubt. Next, he referred to Board's Circular published at (1984) 150 ITR St. 22. This circular states that new Explanation introduced with effect from 1-10-1984 enables Commissioner to revise order under section 263 even when said order is passed by IAC exercising function of ITO under section 125A and that said amendment takes effect from 1-10-1984. 5. Shri P. T. Sanyal replied that Board circular does not help case of department as it clearly states that Explanation takes effect from 1-10- 1984 and not from any earlier date which is clear from amending Act itself. Regarding decision in case of Bejoy Kumar Almal (supra) he stated that it was not declaratory legislation. Consequently, it cannot be said that there was any doubt regarding matter before said amendment came into effect. On other hand, Explanation to section 263 expressly dealers that there was doubt prior to amendment which was being clarified by amendment. Further, Court has held that normally there is as presumption that explanatory provision is retrospective. But, where there is indication to contrary said presumption is rebutted. In this case, he pointed out that legislature clarifies its intention to make certain amendment retrospective right from beginning when it does not mention any date with effect from which amendment would come into force. Alternatively, Legislature sometimes expressly states that clarification shall be deemed to be existing always in Act right from beginning. In absence of any such express legislation, he urged that amendment will take effect only from date from which section expressly makes it effective, and not with effect from any prior date. 6. We have considered contentions of both parties. short question that is raised in this ground is whether section 125A (4) empowers Commissioner to assume jurisdiction under section 263 and revise assessment order made by IAC under section 125A (1) even before 1-10- 1984? There is no doubt that he can do so after 1-10-1984 because of coming into force of Explanation to section 263 with effect from that date. But what is legal position prior to that date? We find that case of Bejoy Kumar Almal (supra) deals with Explanation to section 26 which does not specifically state that it is declaring meaning of any provision of Act for removal of doubts. Hence, in our opinion, said decision cannot be pressed into service to further case of revenue. Similarly, circular of Board printed at (1984) 150 ITR St. 22 is also of no help in resolving issue. We find that Explanation to section 263 like Explanation 2 to section 37(2A) of Act begins with words 'For removal of doubts, it is hereby declared .....'. Both these Explanations are, therefore, clarificatory pieces of legislation expressly enacted to remove doubts which existed relating to their subject matter. In other words, legislature has recognised fact that doubt did exist prior to amendment about true meaning of provision and so it enacted clarificatory amendment in order to remove doubt. Both above Explanations are given effect to by Legislature itself with effect from specific date and not from any earlier or later date. Explanation 2 to section 37(2A) away introduced by section 17 of Finance Act, 1973 with retrospective effect from 1-4-1976. Explanation to section 263(1) is introduced by section 47 of Taxation Laws (Amendment) Act, 1984 prospectively with effect from 1-10-1984 (This Amending Act received assent of President of India on 14-9-1984). Though former Explanation was given retrospective effect and later Explanation was given retrospective effect and latter Explanation was given prospective effect from future date, yet both were clarificatory in nature in order to remove doubts recognises by legislature as existing prior to amendment by very language of amendments and both Explanations were given effect to from specific dates. In our opinion, it is significant that these Explanations were given effect from specific dates. In short contrast to above position, we find that section 4 of Finance Act, 1983, states that 'the following clause shall be inserted and shall be deemed always to have been inserted ......'. It is, therefore, clear that intention of Legislature while enacting section 4 was that said amendment would have retrospective effect not from any specific date but right from beginning. In absence of such clear language in section 47 , it is not possible to infer that Legislature intended to give effect to said amendment right from beginning. In fact, Explanation to section 263 has not been given effect to even from date on which said amendment became law; it has been given effect rebut presumption in favour of retrospective operation of this clarificatory piece of legislation, as pointed out by Court in cases of Bejoy Kumar Almal (supra). 7. For above reasons, we come to conclusion that Explanation t o section 263(1) did not have effect prior to 1-10-1984 and so it was not available to Commissioner for assuming jurisdiction under section 263. If said Explanation was not available for assuming jurisdiction, then question arises as to whether Commissioner can assume jurisdiction because of section 125A (4) as stated in his order under appeal. We do not think so. Firstly, in matters of assuming jurisdiction, there should lie clear and unambiguous provision conferring jurisdiction on particular authority. Explanation to section 263(1) , by its express language, recognises existence of doubt in this regard. Had there been no such doubt, there would have been no need to enact said amendment. Section 125A (4) states that where IAC performs function of ITO, then reference to ITO in Act shall be deemed to be reference to IAC. However, sub-section does not end there. It goes on to say that in such cases, IAC making assessment need not obtain prior approval of IAC whenever any other provisions of Act require such approval to be obtained. It may be that purpose of section 125A (4) was only to avoid assessing IAC to obtain prior approval from himself and not for conferring jurisdiction on Commissioner for purpose of section 263. doubt which existed prior to amendment might be above doubt which existed prior to amendment might be above doubt or any other doubt. It is not necessary for us to find out in what way section 125A (4) left doubt vis-a- vis jurisdiction of Commissioner under section 263. But Legislature has stated in clear language that such doubt existed and so it introduced Explanation to section 263(1) with effect from 1-10-1984 and not with effect from any other date before or after. As has been held in case of Vegetable Products Ltd. (supra), wherever there is reasonable doubt about meaning of provisions in taxing statute, it has to be resolved in favour of assessee. Thus, this argument of conclusion of ours. Hence, we come to conclusion that assumption of jurisdiction under section 263 by Commissioner on 11-11-1983 against order of assessment passed by IAC was bad in law and is not sustainable. Hence, we cancel said order. 8. In view of above decisions or ours, it is not necessary to consider remaining grounds in this appeal. 9. In result, appeal is allowed. *** BROOKE BOND INDIA LTD. v. INSPECTING ASSISTANT COMMISSIONER