Held that the Commissioner (Appeals) is  duty-bound to follow procedure laid down in section 251(2) of the Act. Once the assessee had made a statement that no opportunity was provided by the Commissioner (Appeals) before treating the income as adventure in the nature of trade and the order sheet maintained by the Commissioner (Appeals) clearly showed that no show-cause notice was issued or query raised by the Commissioner (Appeals), the onus shifted to the Department to prove that opportunity was granted to the assessee before the enhancement. The Department had not brought on record any document to prove that the Commissioner (Appeals) had issued to the assessee to explain the assessee the intention of the Commissioner (Appeals) to treat the income as business income, which had been assessed by the Assessing Officer as capital gains and income from house property. There was no show cause issued by the Commissioner (Appeals) before enhancement. Therefore, the Commissioner (Appeals) had failed to give a reasonable opportunity of showing cause against the enhancement. This failure to issue show cause went to the root of the issue of powers of the Commissioner (Appeals) of enhancement. Therefore, the treatment by the Commissioner (Appeals) of capital gains as business income was not sustainable. Similarly, the treatment of lease rent as business income was not sustainable. S. L. Kapoor v. Jagmohan [1981 AIR 1981 SC 136 applied.(AY.  2010-11, 2011-12)