1 Chronicles 3:3 (BSB)

the fifth was Shephatiah by Abital; and the sixth was Ithream by his wife Eglah.

From 1 Chronicles 3. Also in the ESV.

Commentary on 1 Chronicles 3:3

• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on 1 Chronicles 3:1-9: We had an account of David's sons, Sa2 3:2, etc., and Sa2 5:14, etc. 1. He had many sons; and no doubt wrote as he thought, Psa 127:5. Happy is the man that hath his quiver full of these arrows. 2.
• Jamieson-Fausset-Brown (Reformed), Commentary Critical and Explanatory on the Whole Bible on 1 Chronicles 3:3: Eglah his wife--supposed to be another name of Michal, who, though she had no son after her mockery of David for dancing before the ark [Sa2 6:16, Sa2 6:20], might have had one previous to that time. She has the title of wife appended to her name because she was his proper wife; and the mention of her name last probably arose from the circumstance...
• Adam Clarke (Methodist), Clarke's Commentary on the Bible on 1 Chronicles 3:3: By Eglah his wide - The Targum, Jarchi, and others, maintain that this was Michal, the daughter of Saul; but this does not well agree with Sa2 6:23 : Michal had no child to the day of her death. Yet she might have had a child before the time that is mentioned above.
• Keil & Delitzsch (Lutheran), Biblical Commentary on the Old Testament on 1 Chronicles 3:1-4: 1Ch 3:1-4 The sons of David: (a) Those born in Hebron; (b) those born in Jerusalem. - 1Ch 3:1-4. The six sons born in Hebron are enumerated also in 2Sa 3:2-5, with mention of their mother as here: but there the second is called כּלאב; here, on the contrary, דּניּאל, - a difference which cannot well have arisen through an error of a copyist, but...