Hebrews 5:6

As he saith also in another place
Or psalm; namely, in ( Psalms 110:4 ) that is, the same person, even God the Father; who spake the words before cited, also expressed the following:

thou art a priest for ever, after the order of Melchisedec;
that the psalm, from whence these words are taken, belongs to the Messiah, (See Gill on Matthew 22:44) and this very passage is applied unto him by the Jewish writers ^F3; and had not this been the general sense of the Jewish church at this time, the apostle writing to Hebrews would not have produced it; and it very clearly expresses the priesthood of Christ, the eternity of it, and the order according to which it was; and it being not according to the order of Aaron, but of another, shows the change of the priesthood, and so of the law; of Melchizedek, (See Gill on Hebrews 7:1)