Matsyapurana 141.25

141.25

paurṇamāsyāṃ sa dṛśyeta śuklaḥ sampūrṇamaṇḍalaḥ
evamāpyāyitaḥ somaḥ śuklapakṣe 'pyahaḥkramāt
devaiḥ pītasudhaṃ somaṃ purā paścātpibedraviḥ //

The Sun acts daily (in the bright fortnight) as a feeder through His Suṣumṇâ ray when the store of lunar ambrosia is all drunk out by the Devas and the Pitṛis The Moon waxes in his phases day by day by thus being fed through Suṣumṇâ ray in the bright fortnight The Moon wanes in the dark fortnight and waxes in the bright fortnight The moon is nourished thus by the Sun The Moon looks full and white on the full moon night (Pûrṇamâsi) In this way, the Sun by means of his single ray increases the Moon and makes it full of nectar The Devas first drink the nectar of the Moon, then the Sun drinks The Sun drinks every day one digit and does so for fifteen days, He, again in the bright fortnight fills it up by His Suṣumṇâ ray—21 25