The Feast of the Passover: Purification Necessary to the Due Observance of

And on the fourteenth day of the second month they slaughtered the Passover lamb. The priests and Levites were ashamed, and they consecrated themselves and brought burnt offerings to the house of the LORD. …

Now the Jewish Passover was near, and many people went up from the country to Jerusalem to purify themselves before the Passover.