2 Samuel 3:5

“And the sixth, Ithream, by Eglah David’s wife, etc.] Who also is not spoken of in any other place; only, in a like chronological account as the former, it is remarked that the mother of this only is called David’s wife; the reason of which is supposed to be, either because she was a person of no note, and had nothing else to distinguish her; but the same may be said of the two foregoing; or because she was his beloved wife, his heifer, as her name signifies; hence the Jews f51 take her to be Michal his first wife, whom he greatly loved, and who, though she had no children after her contempt of David for playing before the ark, unto the day of her death, yet might have before: but it should…”

“Eglah David's wife--This addition has led many to think that Eglah was another name for Michal, the first and proper wife, who, though she had no family after her insolent ridicule of David (Sa2 6:23), might have had a child before.”

“Eglah - This is added, either because she was of obscure parentage, and was known by no other title but her relation to David: 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, Sa2 6:23, yet might have one before that time. And she might be named the last, because she was given away from David, and married to another man. Six sons in seven years. Some have had as numerous an offspring, and with much more honour and comfort, by one wife. And we know not that any of the six were famous: but three were very infamous. 2 Kings (2 Samuel) 3:6”