2 Chronicles 30:3
For they could not keep it at that time, because the priests had not sanctified themselves sufficiently, neither had the people assembled themselves at Jerusalem.
2 Chronicles 29:34
But the priests were too few, so that they could not flay all the burnt-offerings: wherefore their brethren the Levites helped them, till the work was ended, and until the other priests had sanctified themselves: for the Levites were more upright in heart to sanctify themselves than the priests.
Exodus 12:6
And ye shall keep it until the fourteenth day of the same month: and the whole assembly of the congregation of Israel shall kill it in the evening.
Exodus 12:18
In the first month, on the fourteenth day of the month at evening, ye shall eat unleavened bread, till the one and twentieth day of the month at evening.
2 Chronicles 29:17
Now they began on the first day of the first month to sanctify, and on the eighth day of the month they came to the porch of the LORD: so they sanctified the house of the LORD in eight days; and on the sixteenth day of the first month they made an end.