15:8 And when Asa heard these words, and the prophecy of Oded the prophet, he took courage, and put away the abominable idols out of all the land of Judah and Benjamin, and out of the cities which he had taken from mount Ephraim, and renewed the altar of the LORD, that was before the porch of the LORD.
15:10 So they gathered themselves together at Jerusalem in the third month, in the fifteenth year of the reign of Asa.
Chapter 14 describes the outward prosperity of the kingdom, and Asa's superficial reformation; chapter 15 the true reformation.
15:16 And also concerning Maachah the mother of Asa the king, he removed her from being queen, because she had made an idol in a grove: and Asa cut down her idol, and stamped it, and burnt it at the brook Kidron.
15:17 But the high places were not taken away out of Israel: nevertheless the heart of Asa was perfect all his days.
mother i.e. grandmother. 1 Kings 15:13,
i.e. the northen or ten-tribe kingdom.