More on the separation 7 days before Yom Kippur or the parah adumah (red heifer), as it happens, where each kohen then needs sprinkling as part of the process, but not on the fourth day. The question of when these 7 days fall out is left to the calendar for Yom Kippur, but rigged for the parah adumah. Plus, the chamber where the kohen would go to be sequestered in the Beit HaMikdash - what was it called and why? They changed every 12 months... Why?