Srimad Bhagavatam Canto 11, Chapter 04, Text 20

SB 11.4.20

devasure yudhi ca daitya-patin surarthe
 hatvantaresu bhuvanany adadhat kalabhih
bhutvatha vamana imam aharad baleh ksmam
 yacña-cchalena samadad aditeh sutebhyah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
The Supreme Lord regularly takes advantage of the wars between the demons and demigods to kill the leaders of the demons. The Lord thus encourages the demigods by protecting the universe through His various incarnations during the reigns of each Manu. The Lord also appeared as Vamana and took the earth away from Bali Maharaja on the plea of begging three steps of land. The Lord then returned the entire world to the sons of Aditi.
Srimad Bhagavatam Canto 11, Chapter 04, Text 19
Srimad Bhagavatam Canto 11, Chapter 04, Text 21