Hebrews 7:3

“Without father, without mother, without descent, etc..] Which is to be understood not of his person, but of his priesthood; that his father was not a priest, nor did his mother descend from any in that office; nor had he either a predecessor or a successor in it, as appears from any authentic accounts: or this is to be interpreted, not of his natural, but scriptural being; for no doubt, as he was a mere man, he had a father, and a mother, and a natural lineage and descent; but of these no mention is made in Scripture, and therefore said to be without them; and so the Syriac version renders it; “whose father and mother are not written in the genealogies”; or there is no genealogical account…”

“Without father, &c.--explained by "without genealogy" (so the Greek is for "without descent); compare Heb 7:6, that is, his genealogy is not known, whereas a Levitical priest could not dispense with the proof of his descent. having neither beginning of days nor end of life--namely, history not having recorded his beginning nor end, as it has the beginning and end of Aaron. The Greek idiom expressed by "without father," &c., one whose parentage was humble or unknown. "Days" mean his time of discharging his function. So the eternity spoken of in Psa 110:4 is that of the priestly office chiefly. made like--It is not said that he was asbsolutely "like." Made like, namely, in the particulars here…”

“Without father - The phrase “without father” - ἀπάτωρ apatōr - means literally one who has no father; one who has lost his father; one who is an orphan. Then it denotes one who is born after the death of his father; then one whose father is unknown - “spurious. Passow.” The word occurs often in these senses in the classic writers, for numerous examples of which the reader may consult Wetstein in loc. It is morally certain, however, that the apostle did not use the word here in either of the senses, for there is no evidence that Melchizedek was “fatherless” in any of these respects. It was very important in the estimation of the Jews that the line of their priesthood should be carefully…”

“Without father, without mother, without pedigree - Recorded, without any account of his descent from any ancestors of the priestly order. Having neither beginning of days, nor end of life - Mentioned by Moses. But being - In all these respects. Made like the Son of God - Who is really without father, as to his human nature; without mother, as to his divine; and in this also, without pedigree - Neither descended from any ancestors of the priestly order. Remaineth a priest continually - Nothing is recorded of the death or successor of Melchisedec. But Christ alone does really remain without death, and without successor. Hebrews 7:4”

“7:3 That we have no record of Melchizedek’s father or mother or any of his ancestors is significant in light of the ancestral requirement upon which the Levitical priesthood was based. He appears from nowhere—it is as though there is no beginning or end to his life. The author is interpreting Gen 14:17-20 in light of Ps 110:4, which also understands Melchizedek as representing an eternal priesthood. • He remains a priest forever: This contrasts with a Levite, whose priesthood ended when he died (Heb 7:8, 23). • resembling the Son of God: Melchizedek was not an Old Testament appearance of Jesus. Rather, his priesthood and that of Jesus had characteristics in common, in light of Ps 110:4.”

“Without father: That is, as the Syriac renders, "Whose father and mother are not inscribed among the genealogies; and therefore it was not known who he was." descent: Gr. pedigree, Exo 6:18, Exo 6:20-27; Ch1 6:1-3 a priest: Heb 7:17, Heb 7:23-28 Hebrews 7:4”