मासो वै प्रजापतिस्तस्य कृष्णपक्ष एव रयिः शुक्लः प्रणस्तस्मादेत
ऋषयः शुक्ल इष्टं कुर्वन्तीतर इतरस्मिन् ॥ १.१२॥
māso vai prajāpatistasya kṛṣṇapakṣa eva rayiḥ śuklaḥ praṇastasmādeta
ṛṣayaḥ śukla iṣṭaṃ kurvantītara itarasmin .. 1.12..
The month, verily, is Prajapati. Its dark half, verily, is food, rayi; its bright half, the eater, prana. Therefore some rishis perform sacrifice in the bright half, some in the other half.