II Chronicles - Chapter 35
The Hidden Ark
Passover in Jerusalem under Josiah was a festive occasion. The king urged the kohanim to do their service with enthusiasm. He also told them to take the Ark from the Holy of Holies and to conceal it in a hidden vault, to protect it from the foretold siege (see Talmud Yoma 52b). They were told to organize in their family units in order to perform the Temple service and to work alongside their brethren, the Leviim. They should purify themselves and offer the Passover sacrifices, as G-d instructed via Moses.
Josiah donated sheep and goats for use by the people as their Passover offerings; there were 30,000 of them. He also donated 3,000 cattle for other sacrifices. His officers gave gifts to the kohanim and Leviim.
The service got underway and things proceeded pretty smoothly. The Passover sacrifices were roasted in fire and other sacrifices were cooked. They took care of the people and the Leviim made sure that they and the kohanim had Passover offerings of their own. None of the priests or Levites had to forgo their responsibilities in order to offer their own Passover sacrifice, since they were taken care of.
The day went well and the people were able to celebrate the week of Passover. It was a festival unprecedented since the days of the prophet Samuel; none of Josiah's predecessors had celebrated a Passover like it.
After Josiah had set the Temple right, Pharaoh Neco of Egypt declared war against a third party and wished to get there by way of Judah. Josiah sent forces to prevent this. Neco replied that he had no intention of attacking Judah, but that it was G-d's will that he attack the other nation, so Josiah would be well advised to stay out of his way. Josiah would not relent and he tried to sabotage Neco's plans. He was mortally wounded in the skirmish. When he died, he was greatly mourned by his nation and the prophet Jeremiah composed a dirge in his honor. (According to tradition, this dirge is the fourth chapter of Eicha, the Book of Lamentations, which was authored by Jeremiah.)