Jehoshaphat his son reigned in his stead: Jehoshaphat was thirty-five years old when he began to reign over Judah and he reigned twenty-five years (2 Chr 20.31). He ruled about 872–848 B.C. Since this verse begins a new chapter and a new section, the pronoun his may be confusing to readers that start here. Since it clearly refers to Asa, this may be made explicit in translation (so Good News Translation, Bible en français courant, Die Bibel im heutigen Deutsch). For reigned in his stead, see the comments on 1 Chr 19.1 and 2 Chr 9.31.

And strengthened himself against Israel: This clause in Hebrew may be understood in two different ways as follows:

(1) According to Revised Standard Version and Good News Translation (also Revised English Bible, New Jerusalem Bible, New American Bible, An American Translation, Reina-Valera revisada, Biblia Dios Habla Hoy alternative translation), the meaning is that King Jehoshaphat made his own kingdom stronger in order to protect it from attack by the northern kingdom of Israel.
(2) But the Hebrew may also be understood to mean that Jehoshaphat “showed himself strong in Israel” (Biblia Dios Habla Hoy; similarly Bible de Jérusalem, BCI). This understanding takes the word Israel as referring to the southern kingdom since the Chronicler considered that his people in Judah were the “true people of Israel” and not the northern kingdom that bore that name.

Regardless of which interpretation translators follow here, they should indicate the alternative reading in a footnote.

Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on 1-2 Chronicles, Volume 1. (UBS Helps for Translators). Miami: UBS, 2014. For this and other handbooks for translators see here .