Genesis 30:17

And God hearkened unto Leah, and she conceived, and bare Jacob the fifth son.

God heard Leah, and she conceived and bore Jacob his fifth son, one of the sons born to him in his troubled family life that bore the consequences of his selfish plotting. That birth belongs to the account of Jacob's journey to the land of the children of the East, his visit to Laban, his marriages to Leah and Rachel, his fourteen years of service for Laban's two daughters and his sojourn with Laban. It falls between the morning after his dream at Bethel and his return to Canaan.

It is part of the record of Jacob's troubled, polygamous family life with Leah, which was a plain violation of the institution of marriage. Laban's deception of Jacob in the matter of his daughters was a just retribution for the deception Jacob had practiced upon Esau, though Jacob's sin did not justify Laban's. The surrounding account shows God's care for Jacob despite his selfishness and unfaithfulness, prospering him in flocks and herds despite Laban's efforts to deprive him of his right.

Jacob's polygamous family proves that polygamy brings very great unhappiness into every family where it enters and is never anything but evil and wrong, even though it was allowed to remain through the whole Old Testament period because of hardness of heart. The patriarchs' violation does not destroy or lessen the sacred character of marriage. Marriage was made for man before the fall and its sanctity is not derived from the Decalogue, but the seventh commandment guards its sacredness just as the fourth commandment guards the Sabbath.