SB 11.4.20

devāsure yudhi ca daitya-patīn surārthe
 hatvāntareṣu bhuvanāny adadhāt kalābhiḥ
bhūtvātha vāmana imām aharad baleḥ kṣmāṁ
 yācñā-cchalena samadād aditeḥ sutebhyaḥ
Word for word: 
deva-asure — of the demigods and demons; yudhi — in the battle; ca — and; daitya-patīn — the leaders of the demons; sura-arthe — for the sake of the demigods; hatvā — by killing; antareṣu — during the reign of each Manu; bhuvanāni — all the worlds; adadhāt — protected; kalābhiḥ — by His various appearances; bhūtvā — becoming; atha — moreover; vāmanaḥ — the incarnation as a dwarf brāhmaṇa boy; imām — this; aharat — took away; baleḥ — from Bali Mahārāja; kṣmām — earth; yācñā-chalena — on the excuse of begging for charity; samadāt — gave; aditeḥ — of Aditi; sutebhyaḥ — to the sons (the demigods).
Translation: 
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 Vāmana and took the earth away from Bali Mahārāja on the plea of begging three steps of land. The Lord then returned the entire world to the sons of Aditi.