Śatapatha Brāhmaṇa ("of a hundred paths") 3.2.2.4

3.2.2.4

tāmastamite vācaṃ visṛjate | saṃvatsaro vai prajāpatiḥ prajāpatiryajño 'horātre vai saṃvatsara ete hyenam pariplavamāne kurutaḥ so 'hannadīkṣiṣṭa sa rātrim prāpatsa yāvāneva yajño yāvatyasya mātrā tāvantamevaitadāptvā vācaṃ visṛjate

When the sun has set, he breaks silence. Now Pragâpati is the year, since the sacrifice is Pragâpati; and the year is day and night, since these two revolving produce it. He has been consecrated during the day, and he has gained the night: as great as the sacrifice is, as great as is its extent, to that extent has he gained it before he breaks silence.