(לג) וְנֵר֙ הוֹלִ֣יד אֶת־קִ֔ישׁ וְקִ֖ישׁ הוֹלִ֣יד אֶת־שָׁא֑וּל וְשָׁא֗וּל הוֹלִ֤יד אֶת־יְהֽוֹנָתָן֙ וְאֶת־מַלְכִּי־שׁ֔וּעַ וְאֶת־אֲבִֽינָדָ֖ב וְאֶת־אֶשְׁבָּֽעַל׃
(33) Ner begot Kish, Kish begot Saul, Saul begot Jonathan, Malchi-shua, Abinadab, and Eshbaal;
(ב) את יהונתן ואת מלכי שוע ואת אשבעל. אבי נדב הוא ישבי שזוכר בספר שמואל וכן קורא אותו שם אבינדב כשמתו במלחמה, ואשבעל הוא איש בושת בן שאול, ובעל ובשת אחד כי הבעל נקרא בשת כמו שנאמר וינזרו לבשת, וכן אומר שמה מזבחות לבשת מזבחות לקטר לבעל, וכן גדעון נקרא ירובעל ונקרא ירובשת ולא ספר לנו הכתוב על מה נקרא שמו כן, וכן בן יהונתן בשמואל זוכר אותו מפיבשת והנה מריב בעל הנה בעל במקום בשת ומריב במקום מפי כי קרובים הם כי המריבה על פה הוא ונקרא כן על ענין ידוע אצלם לא נודע אצלנו:
Avinadav is Yishvi who is mentioned in the Book of Samuel (I Samuel 14:49) but they referred to him as Avinadav when he died in the war. And Eshbaal is Ishboshet son of Saul. And Ba'al and Boshet are the same because the Ba'al is referred to AS a Boshet (Shame). As it says "And they [Bnei Yisrael] separated themselves to the Shame [Ba'al]" (Hosea 9:10). And there it also speaks about "altars for the Shame" referring to altars to offer incense to the Ba'al. And so too Gideon (a shofet over Israel) is called Yerubaal and also called Yeruboshet and the text does not tell us why his name was called thus. And so too the son of Jonathan in Samuel is mentioned as Mephiboshet but also referred to as Meriv Ba'al. "Ba'al" is used in place of "Boshet" and "Meriv" in place of "Mephi." This is because they are similar. The "merivah" (fighting) is due to the mouth (peh).
דעת סופרים
Da'at Sofrim (commentary by Rabbi Chaim Dov Rabinowitz)
(The following is a paraphrase)
When it was clear that Saul's dynasty was not going to continue, it no longer became applicable to use the word "Ba'al" which means "lord" or "master" in the names of the sons who were members of that dynasty. Therefore, Eshbaal's name became Ishboshet- to demonstrate his shame and embarrassment over the fall of his father and his dynasty. Similarly, Jonathan's son changed his name so that it became "Mephiboshet" and Rizpah's children also changed their names to include the term "Boshet."
