2 Chronicles 34:20
And the king commanded Hilkiah, and Ahikam the son of Shaphan, and Abdon the son of Micah, and Shaphan the scribe, and Asaiah a servant of the king’s, saying, And the king commanded Hilkiah, and Ahikam the son of Shaphan, and Abdon the son of Micah, and Shaphan the scribe, and Asaiah a servant of the king’s, saying,
The command belongs to the days of Josiah, when the book of the law that had been lost was discovered again and brought to light. It was given in sorrow that the law had been lost and neglected for so long. In response Josiah commanded his officials, men in holy office, to go and inquire of the Lord. That inquiry was to be made on behalf of himself and of the people, who had departed from God's statutes.
That seeking of the Lord led to public recognition of sin, to deep repentance and a return to the Lord, and to a covenant to keep God's commandments. The verse therefore teaches that God's revealed law and its instruction must be taken seriously, with seeking of Him when its light exposes wrongdoing, in order to keep it. The response Josiah looked for from the reading of the law is the kind of response John looked for from his own mission.