New Defender's Study Bible Notes
15:16 Maachah the mother of Asa. Maachah was presumably the “Queen Mother” of Judah. She had been Rehoboam’s wife and the mother of Abijah (II Chronicles 11:21; 13:2) and thus was actually Asa’s grandmother. Probably Asa’s real mother (not named in the narrative) had died when Asa was young, so that Maachah had acted as his mother and thus had been honored as queen mother until she began to worship idols, a situation which Asa finally could not allow to continue.