Leviticus

But into the second went the high priest alone once every year, not without blood, which he offered for himself, and for the errors of the people:

Nor yet that he should offer himself often, as the high priest entereth into the holy place every year with blood of others;

And Aaron shall make an atonement upon the horns of it once in a year with the blood of the sin offering of atonements: once in the year shall he make atonement upon it throughout your generations: it is most holy unto the Lord.

In the tabernacle of the congregation without the vail, which is before the testimony, Aaron and his sons shall order it from evening to morning before the Lord: it shall be a statute for ever unto their generations on the behalf of the children of Israel.

For by one offering he hath perfected for ever them that are sanctified.