CC Ādi 5.113
ধর্ম সংস্থাপন করে, অধর্ম সংহার ॥ ১১৩ ॥
dharma saṁsthāpana kare, adharma saṁhāra
In the ages and millenniums of Manu, He appears as different incarnations to establish the principles of real religion and vanquish the principles of irreligion.
The Lord Viṣṇu who lies in the ocean of milk incarnates Himself in various forms to maintain the laws of the cosmos and annihilate the causes of disturbance. Such incarnations are visible in every manv-antara (i.e., in the course of the reign of each Manu, who lives for 71 × 4,320,000 years). Fourteen such Manus take their birth and die, to yield a place for the next, during one day of Brahmā.