John Gill Commentary 1 Samuel 25:43

"David also took Ahinoam of Jezreel; and they became both of them his wives." — 1 Samuel 25:43 (ASV)

And David also took Ahinoam of Jezreel A city in the tribe of Judah, (Joshua 15:56); that is, he took her to wife, and as it seems before Abigail became his wife; see (2 Samuel 3:2 2 Samuel 3:3); and they were also both of them his wives; polygamy, though not agreeably to the law of nature, nor the law of God, was a custom which prevailed in those times, which good men gave into, though not to be commended for it.