Srimad-Bhagavatam: Canto 9 - Chapter 1 - Verse 11
Sanskrit:
निर्दशे च स आगत्य यजस्वेत्याह सोऽब्रवीत् ।दन्ता: पशोर्यज्जायेरन्नथ मेध्यो भवेदिति ॥ ११ ॥
ITRANS:
nirdaśe ca sa āgatyayajasvety āha so ’bravītdantāḥ paśor yaj jāyerannatha medhyo bhaved iti
Translation:
After ten days, Varuṇa came again and said to Hariścandra, “Now you can perform the sacrifice.” Hariścandra replied, “When an animal grows teeth, then it becomes pure enough to be sacrificed.”