וַיְמִתֵ֣הוּ בַעְשָׁ֔א בִּשְׁנַ֣ת שָׁלֹ֔שׁ לְאָסָ֖א מֶ֣לֶךְ יְהוּדָ֑ה וַיִּמְלֹ֖ךְ תַּחְתָּֽיו׃
Even in the third year of Asa king of Judah did Baasa slay him, and reigned in his stead.
Read midrashic interpretation of I Kings 15:28: and classical rabbinic exegesis.