Cross reference
Mark 10:8
8 and the two will become one flesh,' so that they are no longer two, but one flesh.
1 Corinthians 6:16
16 Or don't you know that he who is joined to a prostitute is one body? For, "The two," says he, "will become one flesh."
Genesis 2:24
24 Therefore a man will leave his father and his mother, and will join with his wife, and they will be one flesh.
Ephesians 5:28
28 Even so ought husbands also to love their own wives as their own bodies. He who loves his own wife loves himself.