Athaliah's destruction of the seed royal had left Joash without a natural successor, and his marriage at the earliest suitable age, was, therefore, a matter of state policy. One of his wives in question was probably "Jehoaddan of Jerusalem," the mother of Amaziah 2-Chronicles 25:1, who must have been taken to wife by Joash as early as his 21st year.

And Jehoiada took for him two wives,.... Not for himself; he had a wife who was aunt to King Joash, and he had sons who were concerned with him in anointing him, 2-Chronicles 22:11 and was now upwards of one hundred years of age; but for the king, when he was at an age fit for marriage, he advised him to marry, and proposed wives to him, whom he thought would be agreeable; for, observing what mischief was done both in church and state through Jehoram's marrying Athaliah, he was desirous of preventing any such disagreeable marriage; and as the young king was in all things guided and directed by him, so he was in this; and no doubt they were good women he pitched upon, and proposed to the king; one of them was Jehoadan, 2-Chronicles 25:1, but the name of the other we know not:
and he begat sons and daughters; how many is not said, nor do we read of the names of any of them, but of Amaziah who succeeded him.

Jehoiada took for him two wives--As Jehoiada was now too old to contract such new alliances, the generality of interpreters apply this statement to the young king.