Numbers 19:3

Why is Eleazar chosen to this office and not Aaron? Is it not because that, as the ceremony to be performed in this service rendered the minister himself for a season ceremonially unclean, Aaron must not for a moment only, while acting officially in his high priest's department, be so. Our JESUS, though made sin for us, yet knew no sin: no shadow of uncleanness was in him. Reader! do not forget to remark, that this slaughter of the heifer was not at the sanctuary, but without the camp. And what saith an infallible expositor on this? "JESUS also, that he might sanctify the people with his own blood suffered without the gate." Hebrews 13:12.