'Keep the Passover' in the Bible

Hezekiah sent word to all Israel and to Judah and also wrote letters to Ephraim and Manasseh to come to the house of the Lord at Jerusalem to celebrate the Passover Feast to the Lord God of Israel.

For the king and his officials and all the assembly in Jerusalem had decided to celebrate the Passover in the second month,

So they decided to circulate a proclamation throughout Israel, from Beersheba to Dan, that the people were to come to celebrate the Passover to the Lord God of Israel, at Jerusalem. For they had not celebrated it in great numbers as it was prescribed [for a long time].

So all the service of the Lord was prepared on that day to celebrate the Passover, and to offer burnt offerings on the altar of the Lord, in accordance with the command of King Josiah.