Hebrews 5:6

and again, Thou art a priest forever, after the order of Melchizedek.

Hebrews 7:17

For the words are in evidence, Thou art a priest forever after the order of Melchizedek.

Hebrews 7:21

For although those priests became such without an oath, He had an oath form God who said to him, The Lord hath sworn and will not change, Thou art a priest forever.

Hebrews 5:10

while God himself pronounced him High Priest according to the order of Melchizedek.

Hebrews 6:20

whither Jesus himself is entered as a forerunner on our behalf, having become a priest forever, after the order of Melchizedek.

Hebrews 7:3

without father or mother, without lineage, having neither beginning of days nor end of life, but resembling the Son of God, he remains a priest in perpetuity.

Hebrews 7:15

And this is yet more abundantly clear if, after the likeness of Melchizedek, there arises another Priest,

Treasury of Scripture Knowledge

Summary

As he saith also in another place, Thou art a priest for ever after the order of Melchisedec.

General references

Bible References

Thou

Hebrews 5:10
while God himself pronounced him High Priest according to the order of Melchizedek.
Hebrews 6:20
whither Jesus himself is entered as a forerunner on our behalf, having become a priest forever, after the order of Melchizedek.
Hebrews 7:3
without father or mother, without lineage, having neither beginning of days nor end of life, but resembling the Son of God, he remains a priest in perpetuity.

General references

Hebrews 5:10
while God himself pronounced him High Priest according to the order of Melchizedek.
Hebrews 7:17
For the words are in evidence, Thou art a priest forever after the order of Melchizedek.