Manusmriti

siva.sh/manusmriti/1/79

यद् प्राग् द्वादशसाहस्रमुदितं दैविकं युगम् । तदेकसप्ततिगुणं मन्वन्तरमिहोच्यते ॥ ७९ ॥

sanskrit

The before-mentioned age of the gods, (or) twelve thousand (of their years), being multiplied by seventy one, (constitutes what) is here named the period of a Manu (Manvantara).

english translation

yad prAg dvAdazasAhasramuditaM daivikaM yugam | tadekasaptatiguNaM manvantaramihocyate || 79 ||

hk transliteration by Sanscript