4 Bible Verses about Atonement, in OT

but into the inner tent the high priest only goes alone, once a year, and that not without blood, which he offers for himself and for the ignorances of the people.

almost everything is purified by blood, and without the shedding of blood there is no remission of sins.

For every high priest chosen from time to time from among men is appointed on behalf of men, in matters relating to God, to offer both gifts and sacrifices on behalf of sins. He is able to deal gently with the ignorant and erring, since he himself also is encompassed with moral weakness, and because of this weakness he is bound to offer sin-offerings not only for the people, but also for himself.

For every high priest chosen from time to time from among men is appointed on behalf of men, in matters relating to God, to offer both gifts and sacrifices on behalf of sins.