Genesis 3:22-24

Then the LORD God said, “Humans have become like one of us; they know good and evil. We must keep them from eating some of the fruit from the tree of life, or they will live forever.” So the LORD God forced Adam out of the garden of Eden to work the ground from which he was taken. After God forced humans out of the garden, he placed angels and a sword of fire that flashed around in every direction on its eastern border. This kept people from getting to the tree of life.