Or do you not know that HE WHO IS JOINED TO A HARLOT IS ONE BODY WITH HER? For “the two,” He says, “shall become one flesh.” BUT HE WHO IS JOINED TO THE LORD IS ONE SPIRIT WITH HIM. 1 Corinthians 6:16-17

Therefore a man shall leave his father and mother and be joined to his wife, and THEY SHALL BECOME ONE FLESH. Genesis 2:24