Hebrews 7:21

(For those Priests were made without an oath: but this with an oath, by him þ^t said vnto him, The Lord sware and wil not repent, thou art a Priest for euer after the order of Melchisedec)
- King James Version (1611) - View 1611 Bible Scan

(for they indeed became priests without an oath, but He with an oath through the One who said to Him, "THE LORD HAS SWORN AND WILL NOT CHANGE HIS MIND, 'YOU ARE A PRIEST FOREVER');"
- New American Standard Version (1995)

(for they indeed have been made priests without an oath; but he with an oath by him that saith of him, The Lord sware and will not repent himself, Thou art a priest for ever);
- American Standard Version (1901)

(For those were made priests without an oath, but this one was made a priest with an oath by him who says of him, The Lord gave his oath, which he will not take back, that you are a priest for ever);
- Basic English Bible

(for they are become priests without the swearing of an oath, but he with the swearing of an oath, by him who said, as to him, The Lord has sworn, and will not repent [of it], *Thou* [art] priest for ever [according to the order of Melchisedec];)
- Darby Bible

(For those priests were made without an oath; but this with an oath, by him that said to him, The Lord swore, and will not repent, Thou art a priest for ever after the order of Melchisedec:)
- Webster's Bible

for these men hold office without any oath having been taken, but He holds it attested by an oath from Him who said to Him, "The Lord has sworn and will not recall His words, Thou art a Priest for ever" --
- Weymouth Bible

(for they indeed have been made priests without an oath), but he with an oath by him that says of him, "The Lord swore and will not change his mind, 'You are a priest forever, according to the order of Melchizedek.'"
- World English Bible

but this preest with an ooth, bi hym that seide `to hym, The Lord swoor, and it schal not rewe hym, Thou art a preest with outen ende, bi the ordre of Melchisedech;
- Wycliffe Bible

and he with an oath through Him who is saying unto him, `The Lord sware, and will not repent, Thou [art] a priest -- to the age, according to the order of Melchisedek;')
- Youngs Literal Bible

Wesley's Notes for Hebrews 7:21

7:21 The Lord sware and will not repent - Hence also it appears, that his is an unchangeable priesthood.