Hebrews 9:25-26

Hebrews 9:25-26. Nor yet that he should offer himself often, as the high priest entereth into the holy place every year with blood of others; for then must he often have suffered since the foundation of the world: but now once in the end of the world hath he appeared to put away sin by the sacrifice of himself.

The high priest brought the blood of the animals that were slain for a sin-offering, and hence he came often. He could not bring his own blood, or he would only have come once, but our Saviour has come only once, "to put away sin by the sacrifice of himself "