i.e. God by the power of his grace inclined their hearts to a unanimous compliance with God's and the king's will. And this is mentioned as the reason of this wonderful change wrought in these men, who had lately been utterly averse from God's worship, and wholly given up to idolatry; as was noted before on 2 Chronicles 29:36.
Related Commentaries of 2 Chronicles 30:12
2 Chronicles 30:12
12 Also in Judah the hand of God was to give them one heart to do the commandment of the king and of the princes, by the word of the LORD.