2 Kings 23:21
“And the king commanded all the people, saying, Keep the passover unto the Lord your God, as it is written in the book of this covenant.”
And all the houses also of the high places that were in the cities of Samaria, which the kings of Israel had made to provoke the Lord to anger, Josiah took away, and did to them according to all the acts that he had done in Beth–el.
And he slew all the priests of the high places that were there upon the altars, and burned men’s bones upon them, and returned to Jerusalem.
And the king commanded all the people, saying, Keep the passover unto the Lord your God, as it is written in the book of this covenant.
Surely there was not holden such a passover from the days of the judges that judged Israel, nor in all the days of the kings of Israel, nor of the kings of Judah;
But in the eighteenth year of king Josiah, wherein this passover was holden to the Lord in Jerusalem.
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Related Verses
“And the king stood by a pillar, and made a covenant before the Lord, to walk after the Lord, and to keep his commandments and his testimonies and his statutes with all their heart and all their soul, to perform the words of this covenant that were written in this book. And all the people stood to the covenant.”
“And the king stood in his place, and made a covenant before the Lord, to walk after the Lord, and to keep his commandments, and his testimonies, and his statutes, with all his heart, and with all his soul, to perform the words of the covenant which are written in this book.”
“And the statutes, and the ordinances, and the law, and the commandment, which he wrote for you, ye shall observe to do for evermore; and ye shall not fear other gods.”
“So they established a decree to make proclamation throughout all Israel, from Beer–sheba even to Dan, that they should come to keep the passover unto the Lord God of Israel at Jerusalem: for they had not done it of a long time in such sort as it was written.”
“And he caused all that were present in Jerusalem and Benjamin to stand to it. And the inhabitants of Jerusalem did according to the covenant of God, the God of their fathers.”