Jamieson, Fausset and Brown on Genesis 2:24

24. one flesh--The human pair differed from all other pairs, that by peculiar formation of Eve, they were one. And this passage is appealed to by our Lord as the divine institution of marriage (Mt 19:4, 5; Ep 5:28). Thus Adam appears as a creature formed after the image of God--showing his knowledge by giving names to the animals, his righteousness by his approval of the marriage relation, and his holiness by his principles and feelings, and finding gratification in the service and enjoyment of God.