The revisional powers cannot be exercised for directing a fuller inquiry to merely find out if the earlier view taken is erroneous particularly when a view was already taken after inquiry. If such course of action as interpreted by the Revisional CIT in the light of the Expln. 2 is permitted, Revisional CIT can possibly find fault with each and every assessment order without himself making any inquiry or verification and without establishing that assessment order is not sustainable in law. This would inevitably mean that every order of the lower authority would thus become susceptible to s. 263 of the Act and, in turn, will cause serious unintended hardship to the taxpayer concerned for no fault on his part. Apparently, this is not intended by the Explanation. Howsoever wide the scope of Expln. 2(a) may be, its limits are implicit in it. It is only in a very gross case of inadequacy in inquiry or where inquiry is per se mandated on the basis of record available before the AO and such inquiry was not conducted, the revisional power so conferred can be exercised to invalidate the action of AO. The AO in the present case has not accepted the submissions of the assessee on various issues summarily but has shown appetite for inquiry and verifications. The AO has passed the order in great detail after making several allowances and disallowances on the issues involved impliedly after due application of mind. Therefore, the Expln. 2 to s. 263 of the Act do not, in our view, thwart the assessment process in the facts and the context of the case. Consequently, we find that the foundation for exercise of revisional jurisdiction is sorely missing in the present case. 10. Resultantly, the order of the Principal CIT passed under s. 263 of the Act is set aside and cancelled and the order of the AO under s. 143(3) is restored. 11.In the result, the appeal of the assessee is allowed.