Genesis 3:24
So He drove out the man and stationed cherubim on the east side of the Garden of Eden, along with a whirling sword of flame to guard the way to the tree of life.
What it says
God drives out the man and places cherubim and a whirling flaming sword east of Eden to guard the way to the tree of life.
What it is doing
It seals the expulsion by closing the path back into the garden.
In context
21And the LORD God made garments of skin for Adam and his wife, and He clothed them. 22Then the LORD God said, “Behold, the man has become like one of Us, knowing good and evil. And now, lest he reach out his hand and take also from the tree of life, and eat, and live forever...” 23Therefore the LORD God banished him from the Garden of Eden to work the ground from which he had been taken. 24So He drove out the man and stationed cherubim on the east side of the Garden of Eden, along with a whirling sword of flame to guard the way to the tree of life.