Adam Clarke on 2 Kings 23:19

That were in the cities of Samaria - Israel had now no king; and Josiah, of the blood royal of Judah, had certainly a direct right to the kingdom; he had, at this time, an especial commission from God, to reform every abuse through the whole land - all that ground that was given by the Lord as an inheritance to the twelve sons of Jacob. Therefore he had every right to carry his plans of reformation into the Samaritan states.