I Samuel 25:43-44 The Dawn Of David’s Polygamy.
Couched in the history of Saul and David are some significant developments such as we find here. After a long passage extolling the virtues of Abigail, and David’s subsequent marriage to her after Nabal died, we find this comment, that “David also took Ahinoam of Jezreel, and so both of them were his wives.” (v. 43) Sadly, the first instance we have of someone breaking the creation covenant norm of one man and one woman was the wicked member of the ungodly seed – Lamech, the direct descendant of Cain who murdered his brother Abel – the godly seed (Gen. 4:19). It seems to come as some kind of rational that the reason David took a second then a third wife was because “Saul had given Michal his daughter, David’s wife, to Palti the son of Laish, who was from Gallim.” (v. 44).