Section 143(1), 147 & 148 of the Income Tax Act, 1961 — Reassessment — To reopen an assessment under section 147 based on the original return filed by the assessee would be a case of change of opinion and consequently bad in law. The language employed in section 147 does not make any distinction between an order passed under section 143(3) and the intimation issued under section 143(1) and therefore, it is not permissible to adopt different standards while interpreting the words "reasons to believe" vis a vis section 143(3) & 143(1)— Tenzing Match Works vs. Deputy Commissioner of income tax [2019] 419 ITR 338 (Madras)