1 Kings 15:17 - Matthew Poole's English Annotations on the Holy Bible

Baasha went up against Judah; perceiving Asa's great success, of which see 2Ch 14 2Ch 15, and the defection of many of his own subjects to him upon that occasion, 2 Chronicles 15:9, he began to bestir himself, and commenceth a war against him. Built, i.e. repaired and fortified, Ramah, a city of Benjamin; which either belonged to the kingdom of Israel, from the division, (as some other places of that tribe are supposed to have done; of which See Poole on "1 Kings 11:13",) or belonged to Judah, but was now invaded and taken by Baasha, and fortified. That he might not suffer any to go out or come in to Asa king of Judah; therefore he chose this place, because it was in the way from his kingdom to Jerusalem, and, as some add, in or near the straits of the mountains, where they could easily discover and hinder all passengers that way.