For a large number of the people—many from Ephraim, Manasseh, Issachar, and Zebulun—were unclean, yet they had eaten the Passover contrary to what was written. But Hezekiah had interceded for them, saying, "May the good LORD provide atonement on behalf of whoever sets his whole heart on seeking God, the LORD God of his ancestors, even though not according to the purification [rules] of the sanctuary." So the LORD heard Hezekiah and healed the people.
2 Chronicles 30:18-20
I love it when we get glimpses of Jesus in the Old Testament. Look at what happened here... many of God's people were unclean and had eaten the Passover in an unclean state. They were not right before God. They had not fulfilled the correct purification laws. And what did Hezekiah pray in such a tricky situation? "LORD, please provide the atonement yourself, for those whose hearts are set on you". There is the gospel! God himself has provided the Lamb and when we find ourselves not measuring up to the Law but seek Him with all our hearts and trust in the sacrifice that He has provided himself in Jesus, then He will turn and heal and save us. What God provides Himself is all that is needed. Later on in the passage it says that everyone rejoiced, "Such rejoicing had not been seen in Jerusalem since the days of Solomon, son of David..." v26. Let's turn to Jesus with our whole heart, let Him heal us and bring us joy :)