John Gill Commentary 2 Chronicles 28:1

"Ahaz was twenty years old when he began to reign; and he reigned sixteen years in Jerusalem: and he did not that which was right in the eyes of Jehovah, like David his father;" — 2 Chronicles 28:1 (ASV)

Ver. 1-4. Ahaz was twenty years old when he began to reign

2 Chronicles 28:2

(See Gill on 2 Chronicles 28:1)