וַיַּשְׁלֵ֥ם יְהוֹשָׁפָ֖ט עִם־מֶ֥לֶךְ יִשְׂרָאֵֽל׃
Josafat schloss Frieden mit dem König von Israel.
Rashi
Yehoshofot made peace with the king of Yisroel. Since there was war between Asa his father and Basha the king of Yisroel, it was necessary to say this.