Hebrews 7:23

The former priests, on the one hand, existed in greater numbers because they were prevented by death from continuing,

1 Chronicles 6:3-14

The children of Amram were Aaron, Moses and Miriam. And the sons of Aaron were Nadab, Abihu, Eleazar and Ithamar.

Nehemiah 12:10-11

Jeshua became the father of Joiakim, and Joiakim became the father of Eliashib, and Eliashib became the father of Joiada,

Hebrews 7:8

In this case mortal men receive tithes, but in that case one receives them, of whom it is witnessed that he lives on.

Treasury of Scripture Knowledge

Summary

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

General references

Bible References

Were

Hebrews 7:8
In this case mortal men receive tithes, but in that case one receives them, of whom it is witnessed that he lives on.
1 Chronicles 6:3
The children of Amram were Aaron, Moses and Miriam. And the sons of Aaron were Nadab, Abihu, Eleazar and Ithamar.
Nehemiah 12:10
Jeshua became the father of Joiakim, and Joiakim became the father of Eliashib, and Eliashib became the father of Joiada,

General references

Numbers 20:26
and strip Aaron of his garments and put them on his son Eleazar. So Aaron will be gathered to his people, and will die there.”
Zechariah 1:5
“Your fathers, where are they? And the prophets, do they live forever?