2 Kings 16:2

2. Twenty years old… sixteen years So his whole age was thirty-six years. But he was immediately succeeded by his son Hezekiah, who was at the time twenty-five years old. 2 Kings 18:2. Accordingly Ahaz must have begotten his son Hezekiah when he was only eleven years old. To meet this difficulty some copies of the Septuagint, and the Syriac and Arabic versions at the parallel place in Chronicles (2 Chronicles 28:1,) read twenty-five instead of twenty years. But most interpreters accept the common reading, and argue that it was nowise impossible for Ahaz to beget a son in his eleventh or twelfth year. Compare note on 2 Kings 18:2.