For if he were on earth, etc. It is now beyond dispute that Christ is a high priest; but as the office of a judge does not exist without laws and statutes, so the office of sacrificing must be connected with Christ as a priest: yet he has no earthly or visible sacrifice; he cannot then be a priest on earth. We must always hold this truth that when the Apostle speaks of the death of Christ, he regards not the external action, but the spiritual benefit. He suffered death as men do, but as a priest he atoned for the sins of the world in a divine manner; there was an external shedding of blood, but there was also an internal and spiritual purgation; in a word, he died on earth, but the virtue and efficacy of his death proceeded from heaven. What immediately follows some render thus, "He could not be a priest of the number of those who offer gifts according to the Law." But the words of the Apostle mean another thing; and therefore I prefer this rendering, "He could not be a priest as long as there are priests who," etc. For he intends to show one of these two things, either that Christ is no priest, while the priesthood of the Law continued, as he had no sacrifice, or that the sacrifices of the law ceased as soon as Christ appeared. The first of these is against all reason, for it is an act of impiety to deprive Christ of his priesthood. It then remains for us to confess, that the Levitical order is now abolished.

For if he were on earth, he should not be a priest - He could not perform that office. The design of this is, to show a reason why he was removed to heaven. The reason was, that on earth there were those who were set apart to that office, and that he, not being of the same tribe with them, could not officiate as priest. There was an order of people here on earth consecrated already to that office, and hence, it was necessary that the Lord Jesus, in performing the functions of the office, should be removed to another sphere.

For if he were on earth - As the Jewish temple was standing when this epistle was written, the whole temple service continued to be performed by the legal priests, descendants of Aaron, of the tribe of Levi; therefore if Christ had been then on earth, he could not have performed the office of a priest, being of the tribe of Judah, to which tribe the office of the priesthood did not appertain.
There are priests that offer gifts - This is an additional proof that this epistle was written before the destruction of Jerusalem. As the word θυσιαι, sacrifices, is not added here as it is in Hebrews 8:3, is it any evidence that bloody sacrifices had then ceased to be offered? Or, are both kinds included in the word δωρα, gifts? But is δωρον, a gift, ever used to express a bloody sacrifice? I believe the Septuagint never used it for זבח zebach, which signifies an animal offered to God in sacrifice.

(5) For if he were on earth, he should not be a priest, seeing that there are priests that offer gifts according to the law:
(5) He gives a reason why he said that our High Priest is in the heavenly sanctuary, and not in the earthly: because, says he, if he were now on the earth, he could not minister in the earthly sanctuary, seeing there are still Levitical priests who are appointed for him, that is to say, to be patterns of that perfect example. To what purpose should the patterns serve, when the true and original example is present?

For if he were on earth, he should not be a priest,.... The Socinians from hence attempt to prove that Christ was not a priest, and did not offer sacrifice on earth; whereas his coming into the world, and his appearance in human nature, was in the character of a priest, and to qualify himself for one; his death was his sacrifice, which was on earth; and he never offered but one sacrifice; and it was after he had offered himself that he went to heaven; so the sacrifices under the law were first offered, before their blood was carried within: but the meaning is, either if "that" was on earth, namely, what it was necessary he should have to offer; if his human nature had been earthly, had been of men, had come by ordinary generation, he had not been properly, only typically a priest, at most; and had been no better than the typical ones; yea, he would have been needless, nay, might not have offered, not being of Levi's tribe, and could not have existed as a priest with the sons of Aaron; but he had his human nature in another way, through the power of the Holy Ghost from above, and therefore is said to come from above, from heaven, and to be the Lord from heaven: or the sense is, if he was on earth, and had not died, he had not been a priest; and if he had died and remained under the power of death, he had been a priest of no account and use; and had he rose again and remained on earth, without going to heaven, with his blood and sacrifice, he had not been a perfect priest; if Christ had remained on earth, the Levitical priesthood had remained, and so he would have been no priest, since two priesthoods could not have subsisted together. The Levitical priesthood was in force while Christ was on earth; Christ's priesthood was not perfected on earth; the Levitical priesthood remaining while he was on earth, proves he was not then a perfect priest, or had not completed his priesthood; had he been so, that would not have subsisted; it was necessary therefore that Christ should enter into the holy place, to put an end to the Levitical priesthood: moreover, if he had remained on earth, he had been needless;
seeing that there are priests that offer gifts according to the law; there were priests when Christ was upon earth; their work was to offer gifts the people brought, and sacrifices for sin, and that according to the law of Moses, which till the death of Christ was in full force.

Implying that Christ's priestly office is exercised in heaven, not in earth; in the power of His resurrection life, not of His earthly life.
For--The oldest manuscripts read, "accordingly then."
if, &c.--"if He were on earth, He would not even (so the Greek) be a priest" (compare Hebrews 7:13-14); therefore, certainly, He could not exercise the high priestly function in the earthly Holy of Holies.
seeing that, &c.--"since there are" already, and exist now (the temple service not yet being set aside, as it was on the destruction of Jerusalem), "those (the oldest manuscripts omit 'priests') who offer the (appointed) gifts according to (the) law." Therefore, His sacerdotal "ministry" must be "in the heavens," not on earth (Hebrews 8:1). "If His priesthood terminated on the earth, He would not even be a priest at all" [BENGEL]. I conceive that the denial here of Christ's priesthood on earth does not extend to the sacrifice on the cross which He offered as a priest on earth; but applies only to the crowning work of His priesthood, the bringing of the blood into the Holy of Holies, which He could not have done in the earthly Holy of Holies, as not being an Aaronic priest. The place (the heavenly Holy of Holies) was as essential to the atonement being made as the oblation (the blood). The body was burnt without the gate; but the sanctification was effected by the presentation of the blood within the sanctuary by the high priest. If on earth, He would not be a priest in the sense of the law of Moses ("according to the law" is emphatic).

But if he were on earth - If his priesthood terminated here. He could not be a priest - At all, consistently with the Jewish institutions. There being other priests - To whom alone this office is allotted.