The authorization for the withdrawal of funds from the Consolidated Fund of India must come from

According to Article 266(3) of the Constitution of India, no money can be appropriated out of the Consolidated Fund of India except in accordance with law [3]. The pivot of parliamentary control over the financial system is this fund, which acts as the reservoir for all government revenues and loans [3]. The legal authorization for withdrawal is granted through the enactment of the Appropriation Bill, which must be passed by the Parliament and subsequently receive the President's assent to become an Act [2]. This legislative process ensures that the Executive cannot spend public money without the express sanction of the Parliament [3]. While the President's assent is the final step in the legislative process, the substantive 'authorization' or 'legalization' of payments is a function of the Parliament's power of the purse [2].

Sources

1. [3] Introduction to the Constitution of India, D. D. Basu (26th ed.). > Chapter 12: The Union Legislature > p. 259
2. [1] Laxmikanth, M. Indian Polity. 7th ed., McGraw Hill. > Chapter 23: Parliament > Stages in Enactment > p. 254
3. [2] Indian Polity, M. Laxmikanth(7th ed.) > Chapter 23: Parliament > Stages in Enactment > p. 254