2 Samuel 3:5

David's wife: this is added, either because she was of obscure parentage, and was known by no other title but her relation to David; or to distinguish her from some other person of that name, who possibly might be of no good fame; or because this was his first and most proper wife, best known by her other name of Michal, who, though she had no child by David after she scoffed at him for dancing before the ark, 2 Samuel 6:23, yet might have one before that time. And she might be named the last of these here, because she was given away from David, and married to another man, when David took the other wives; and therefore though she had been first, yet now she was become the last of them. Or this title, being put in the last place, may belong to all the rest of the women above mentioned, by a figure called zeugma, to distinguish them from his concubines, 2 Samuel 5:13 1 Chronicles 3:9.