So long as they two lived and reigned together; which is not so to be understood, as if there were a solemn and declared war continuing all that time, (for Asa was quiet in a great measure for his first ten years, 2 Chronicles 14:1, till the Israelites had recovered themselves from that dreadfull blow given them by Abijah, 2Ch 13, and Baasha began to reign in Asa's third year,) but so that there were many private and particular hostilities practised among them; in which sense the same phrase is used 1 Kings 14:30.
Related Commentaries of 1 Kings 15:16
1 Kings 15:16
16 And there was war between Asa and Baasha king of Israel all their days.