Hebrews 7:11

Therefore if perfection were by the Levitical priesthood (for under it the people received the Law), what further need was there that another priest should rise after the order of Melchizedek, and not be called after the order of Aaron?

Hebrews 8:7

For if that first covenant had been without fault, then no place would have been sought for the second.

Galatians 2:21

I do not set aside the grace of God, for if righteousness is through law, then Christ died without cause.

Hebrews 5:6

As He says also in another place, "You are a priest forever after the order of Melchizedek."

Hebrews 7:17-19

For He testifies, "You are a priest forever after the order of Melchizedek."

Galatians 4:3

Even so we, when we were infants, were in bondage under the elements of the world.

Galatians 4:9

But now, knowing God, but rather are known by God, how do you turn again to the weak and beggarly elements to which you again desire to slave anew?

Colossians 2:10-17

And you are complete in Him, who is the Head of all principality and power,

Hebrews 5:10

being called by God a high priest after the order of Melchizedek;

Hebrews 6:20

where the Forerunner has entered for us, even Jesus, having become a high priest forever after the order of Melchizedek.

Hebrews 7:15

And it is still far more evident, since there arises another priest after the likeness of Melchizedek,

Hebrews 7:21

(for those priests were made without an oath, but this one was made with an oath by Him who said to Him, "The Lord swore and will not repent, You are a priest forever after the order of Melchizedek,")

Hebrews 8:10-13

"For this is the covenant that I will make with the house of Israel after those days, says the Lord: I will put My Laws into their mind and write them in their hearts, and I will be their God, and they shall be My people.

Hebrews 10:1-4

For the Law which has a shadow of good things to come, not the very image of the things, appearing year by year with the same sacrifices, which they offer continually, they are never able to perfect those drawing near.

Treasury of Scripture Knowledge

Summary

If therefore perfection were by the Levitical priesthood, (for under it the people received the law,) what further need was there that another priest should rise after the order of Melchisedec, and not be called after the order of Aaron?

General references

Bible References

Perfection

Hebrews 7:18
For truly there is a putting away of the commandment which went before, because of the weakness and unprofitableness of it.
Hebrews 8:7
For if that first covenant had been without fault, then no place would have been sought for the second.
Hebrews 10:1
For the Law which has a shadow of good things to come, not the very image of the things, appearing year by year with the same sacrifices, which they offer continually, they are never able to perfect those drawing near.
Galatians 2:21
I do not set aside the grace of God, for if righteousness is through law, then Christ died without cause.
Galatians 4:3
Even so we, when we were infants, were in bondage under the elements of the world.
Colossians 2:10
And you are complete in Him, who is the Head of all principality and power,

What

Hebrews 7:26
For such a high priest became us, who is holy, harmless, undefiled, separate from sinners and made higher than the heavens,

Another

Hebrews 7:15
And it is still far more evident, since there arises another priest after the likeness of Melchizedek,
Hebrews 5:6
As He says also in another place, "You are a priest forever after the order of Melchizedek."
Hebrews 6:20
where the Forerunner has entered for us, even Jesus, having become a high priest forever after the order of Melchizedek.

General references

Numbers 20:26
And strip Aaron of his garments, and put them upon Eleazar his son. And Aaron shall be gathered to his people, and shall die there.