In Hebrews 9:23-28, the author is discussing how the Yom Kippur sacrifice prefigured the work of Jesus, who entered not the earthly temple with his blood -- but the heavenly one, to which the earthly temple corresponds. The picture is of Jesus presenting his blood as an atoning sacrifice to the Father for all mankind for all time.
When did this take place? Here is the text itself:
23 Thus it was necessary for the copies of the heavenly things to be purified with these rites, but the heavenly things themselves with better sacrifices than these. 24 For Christ has entered, not into holy places made with hands, which are copies of the true things, but into heaven itself, now to appear in the presence of God on our behalf.25 Nor was it to offer himself repeatedly, as the high priest enters the holy places every year with blood not his own,26 for then he would have had to suffer repeatedly since the foundation of the world. But as it is, he has appearedonce for all at the end of the ages to put away sin by the sacrifice of himself. 27 And just as it is appointed for man to die once, and after that comes judgment, 28 so Christ, having been offered once to bear the sins of many, will appear a second time, not to deal with sin but to save those who are eagerly waiting for him.