Rashi on Genesis 2:24/רש"י על בראשית ב׳:כ״ד

1על כן יעזב איש THEREFORE A MAN LEAVETH — The Divine Spirit says this, thus prohibiting immoral relationship to the “Sons of Noah” also (Sanhedrin 57b).

2לבשר אחד ONE FLESH — Both parents are united in the child.