'Now you shall keep it until the fourteenth day of the same month. Then the whole assembly of the congregation of Israel shall kill it at twilight.

'In the first [month,] on the fourteenth day of the month at evening, you shall eat unleavened bread, until the twenty-first day of the month at evening.

But the priests were too few, so that they could not skin all the burnt offerings; therefore their brethren the Levites helped them until the work was ended and until the [other] priests had sanctified themselves, for the Levites were more diligent in sanctifying themselves than the priests.