Manasseh was twelve years old when he became king, and he reigned in Jerusalem fifty-five years. His mother’s name was Hephzibah.
How delightful were our meditations on the last reign! How many pleasing views had we of Sion in its glory (that is, in its purity and in its triumphs), of the king in his beauty! (for Isa 33:17 refers to Hezekiah), and (as it follows there, Kg2 21:20) Jerusalem was a quiet habitation because a city of righteousness, Isa 1:26.
Commenting on 2 Kings 21:1-9
Manasseh was twelve years old when he began to reign,.... So that he was born three years after Hezekiah's recovery from his sickness, and in the seventeenth year of his reign: and reigned fifty five years in Jerusalem: among which must be reckoned the time of his captivity in Babylon; his reign was the longest of any of the kings of Judah: and his mother's...
Manasseh was twelve years old - He was born about three years after his father's miraculous cure; he was carried captive to Babylon, repented, was restored to his kingdom, put down idolatry, and died at the age of sixty-seven years. See 2 Chronicles 33:1-20.