The first thing that stands out to me about this passage is that it seems like they found the Book of the Law completely by accident. They were cleaning up the temple and just happened to stumble upon it. They’d neglected God’s Word for so long that they’d forgotten about it! No wonder Judah had drifted so far from the Lord! Even the priests didn’t know His Word!
The second thing that stands out is the king’s immediate response: humble repentance. When God points out a sin in our lives, that should be our response as well, even though our instinct may tell us to run and hide.
But God is gracious. And, as He heard King Josiah’s repentant prayer, He hears ours as well.
Father God, thank You for Your grace. Thanks for forgiveness. And thank You for Your Word. May I not neglect it, but live according to it.