The LORD hath sworn, and will not repent, Thou [art] a priest for ever after the order of Melchizedek.
Ver. 4. The Lord hath sworn, &c.] Christ's priestly office, as well as his kingly, is here described, whereof how many and how great mysteries there are, see Heb. vii., with the notes. The Church is collected and conserved not only by Christ's kingly power, but also by his priestly mediation.
Thou art a priest] 1. To expiate. 2. To intercede.
After the order of Melchisedek] Who whether he were Shem, or some other, is not easy to determine. Melchisedek was a king and a priest. Christ was more, a priest, a prophet, and a king. These offices have met double in some others; as Melchisedek was king and priest, Samuel a priest and a prophet, David a king and a prophet; but never met all three in any but in Christ alone.