II Sameul 3:2-5 is a historical record of David's sons who were born in Hebron. This shows he had multiple wives or concubines. There is nothing in this passage, or anywhere in the Bible, that says it is acceptable to God for us to have multiple wives and concubines. Unlike Leviticus 18:22, which is a direct command from God, these passages only describe what happened.

This is what II Samuel 3:2-5 says (NIV):

"Sons were born to David in Hebron:

His firstborn was Amnon the son of Ahinoam of Jezreel; his second, Kileab the son of Abigail the widow of Nabal of Carmel; the third, Absalom the son of Maacah daughter of Talmai king of Geshur; the fourth, Adonijah the son of Haggith; the fifth, Shephatiah the son of Abital; and the sixth, Ithream the son of David's wife Eglah. These were born to David in Hebron."

Everything in the Bible is true. This is a true record of the sons of David born in Hebron. However, not everything in the Bible is intended as an example for us to follow. The people in the Bible were ordinary people (except for Jesus) who, like us, were not perfect.