SB 3.13.47

sa itthaṁ bhagavān urvīṁ
 viṣvaksenaḥ prajāpatiḥ
rasāyā līlayonnītām
 apsu nyasya yayau hariḥ
Synonyms: 
saḥ — He; ittham — in this manner; bhagavān — the Personality of Godhead; urvīm — the earth; viṣvaksenaḥ — another name of Viṣṇu; prajā-patiḥ — the Lord of the living entities; rasāyāḥ — from within the water; līlayā — very easily; unnītām — raised; apsu — on the water; nyasya — placing; yayau — returned to His own abode; hariḥ — the Personality of Godhead.
Translation: 
In this manner the Personality of Godhead, Lord Viṣṇu, the maintainer of all living entities, raised the earth from within the water, and having placed it afloat on the water, He returned to His own abode.
Purport: 

The Personality of Godhead, Lord Viṣṇu, descends by His will to the material planets in His innumerable incarnations for particular purposes, and again He goes back to His own abode. When He descends He is called an avatāra because avatāra means “one who descends.” Neither the Lord Himself nor His specific devotees who come to this earth are ordinary living entities like us.