Canto 1 Chapter 10 Text 25
jivanti tatraisa hi sattvatah kila
dhatte bhagam satyam rtam dayam yaso
bhavaya rupani dadhad yuge yuge
Whenever there are kings and administrators living like animals in the lowest modes of existence, the Lord in His transcendental form manifests His supreme power, the Truth Positive, shows special mercy to the faithful, performs wonderful activities and manifests various transcendental forms as is necessary in different periods and ages.