Hebrews 7:23

Again, new Levitical priests are continually being appointed, because death prevents their remaining in office;

Hebrews 7:8

In the one case the tithes are received by mortal men; in the other case by one about whom there is the statement that his life still continues.

Treasury of Scripture Knowledge

Summary

And they truly were many priests, because they were not suffered to continue by reason of death:

Bible References

Were

Hebrews 7:8
In the one case the tithes are received by mortal men; in the other case by one about whom there is the statement that his life still continues.