2 Chronicles 30:12
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. 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.
The verse belongs to the account of Hezekiah's first Passover and the people's return to obedience, nearly a century before Josiah's reform. The hand of God giving Judah one heart means God moved the people of Judah to share one purpose in obeying the king's and princes' command to keep the Passover, a command in agreement with the word of the Lord as revealed through the prophets. The chapter shows God's people responding to a call to give themselves wholly to Him, with people of all ages coming forward and many speaking with feeling.
God moved some Israelites to humble themselves and join in keeping the Passover, while most mocked or ignored Hezekiah's invitation. In contrast to the northern Israelites who mocked the invitation, people from Asher, Manasseh, and Zebulun humbled themselves and went to Jerusalem for the feast.
That obedience is connected with observing the statutes given through Moses, especially those in Deuteronomy, including the book of the covenant that forms part of Deuteronomy. Provision was made for teaching priests to read the book of the law to the people in public every day. Keeping those statutes recorded by Moses is what made Hezekiah's reign prosperous.