Hebrews 7:3
Without father, without mother, without descent, having neither beginning of days, nor end of life; but made like unto the Son of God; abideth a priest continually. Without father, without mother, without descent, having neither beginning of days, nor end of life; but made like unto the Son of God; abideth a priest continually.
Melchizedek was Jesus Christ Himself appearing in person on earth as King of Salem, meaning King of Peace. His appearing was to reveal the truth of heaven and to perpetuate the law of God. He is proof that God has never left Himself without a witness on the earth, being one of God's appointed, heaven-sent agencies with abundant evidence of divine appointment. Abraham recognized Him as the coming One, declaring Him to be the Messiah, the Prince of Life, and the Redeemer of the world, as witnessed when He comes to Jerusalem.
The verse belongs to the account of the Melchizedek priesthood, under which believers are now living. The tithing system connected with Melchizedek was ordained by God and observed from the earliest times. As God gave it, the system was just and reasonable. Abraham the father of the faithful paid tithes of all that he possessed to Melchizedek.
Abraham's example makes tithe-paying a continuing duty for believers, for if Abraham gave a tithe of all he possessed, that duty applies to believers as well. The obligation itself remains binding, and Christ affirmed that tithes ought to be paid and not left undone, alongside judgment, mercy, and faith.