Shatapatha Brahmana 2.6.3.12

2.6.3.12

atha dīkṣeta taṃ nānījānam punaḥ phālgunī paurṇamāsyabhiparyeyātpunaḥprayāgarūpa iva ha sa yadenamanījānam punaḥ phālgunī paurṇamāsyabhiparyeyāttasmādenaṃ nānījānam punaḥ phālgunī paurṇamāsyabhiparyeyāditi nūtsṛjamānasya

Let him then get consecrated (for the Soma-sacrifice), lest the Phâlguna full-moon again pass by without his offering (Soma). For were the Phâlguna full-moon again to pass by without his having offered (Soma), he would certainly have to begin anew (to perform the Seasonal offerings): hence the Phâlguna full-moon should not again pass by without his offering Soma. Such (is the rule) for him who discontinues (the Seasonal offerings).