2 Kings 12:1
"In the seventh year of Jehu Jehoash began to reign; and forty years reigned he in Jerusalem. And his mother’s name was Zibiah of Beersheba."
Cross References (ranked by relevance)
2 Kings 11:21
Seven years old was Jehoash when he began to reign.
2 Kings 9:27
But when Ahaziah the king of Judah saw this, he fled by the way of the garden house. And Jehu followed after him, and said, Smite him also in the chariot. And they did so at the going up to Gur, which is by Ibleam. And he fled to Megiddo, and died there.
1 Chronicles 3:11
Joram his son, Ahaziah his son, Joash his son,