Section 140 (5) reads as follows:
"A registered person shall be entitled to take, in his electronic credit ledger, credit of eligible duties and taxes in respect of inputs or input services received on or after the appointed day but the duty or tax in respect of which has been paid by the supplier under the 10[existing law, within such time and in such manner as may be prescribed], subject to the condition that the invoice or any other duty or tax paying document of the same was recorded in the books of account of such person within a period of thirty days from the appointed day:
Provided that the period of thirty days may, on sufficient cause being shown, be extended by the Commissioner for a further period not exceeding thirty days:
Provided further that said registered person shall furnish a statement, in such manner as may be prescribed, in respect of credit that has been taken under this sub-section"