Hebrews 9:6-7

Now when these things have been prepared in this way, the priests continually enter the outer [or first section of the] tabernacle [that is, the Holy Place] performing [their ritual acts of] the divine worship, but into the second [inner tabernacle, the Holy of Holies], only the high priest enters [and then only] once a year, and never without [bringing a sacrifice of] blood, which he offers [as a substitutionary atonement] for himself and for the sins of the people committed in ignorance. [Lev 16:15]