Genesis 3:22-24

22 ADONAI, God, said, "See, the man has become like one of us, knowing good and evil. Now, to prevent his putting out his hand and taking also from the tree of life, eating, and living forever -"
23 therefore ADONAI, God, sent him out of the garden of 'Eden to cultivate the ground from which he was taken.
24 So he drove the man out, and he placed at the east of the garden of 'Eden the k'ruvim and a flaming sword which turned in every direction to guard the way to the tree of life.