'Cleansed' in the Bible

Then they went in to Hezekiah the king within [the palace], and said, "We have cleansed all the house of Yahweh, and the altar of burnt offering, with all its vessels, and the table of show bread, with all its vessels.

For a multitude of the people, even many of Ephraim and Manasseh, Issachar and Zebulun, had not cleansed themselves, yet they ate the Passover otherwise than it is written. For Hezekiah had prayed for them, saying, "May the good Yahweh pardon everyone