Genesis 14:18
16 He retrieved all the stolen property. He also brought back his nephew Lot and his possessions, as well as the women and the rest of the people. 17 After Abram returned from defeating Kedorlaomer and the kings who were with him, the king of Sodom went out to meet Abram in the Valley of Shaveh (known as the King’s Valley). 18 Melchizedek king of Salem brought out bread and wine. (Now he was the priest of the Most High God.) 19 He blessed Abram, saying, “Blessed be Abram by the Most High God, Creator of heaven and earth. 20 Worthy of praise is the Most High God, who delivered your enemies into your hand.” Abram gave Melchizedek a tenth of everything.
Philo On Abraham 235
235 And when the great high priest of the most high God beheld him returning and coming back loaded with trophies, in safety himself, with all his own force uninjured, for he had not lost one single man of all those who went out with him; marvelling at the greatness of the exploit, and, as was very natural, considering that he had never met with this success but through the favour of the divine wisdom and alliance, he raised his hands to heaven, and honoured him with prayers in his behalf, and offered up sacrifices of thanksgiving for his victory, and splendidly feasted all those who had had a share in the expedition; rejoicing and sympathising with him as if the success had been his own, and in reality it did greatly concern him. For as the proverb says:-- "All that befalls from friends we common call." And much more are all instances of good fortune common to those whose main object it is to please God.
Notes and References
"... Melchizedek is a priest: although Targum Pseudo-Jonathan does not use the word khn here, Shem is so styled in Targum Pseudo-Jonathan Genesis 38:6, 24. Furthermore, the expression ‘at that time he was ministering’ makes best sense if ‘ministering’, mšmš, is taken to mean ‘acting as priest’, since an ordered temporal succession of priests is attested elsewhere in rabbinic tradition. The title Shem the Great suggests a well-known worthy with a history to his credit: what this might be, we shall discover presently. Targum Pseudo-Jonathan uniquely calls him the righteous king, an interpretation of the name Melchizedek found also in Philo and Josephus. This meaning of the name was known also to the writer of Hebrews 7:2, as is Targum Pseudo-Jonathan’s note that he ‘went out to meet Abram’. None of these unique details in Targum Pseudo-Jonathan seems directed against Christianity. Rather, the Epistle to the Hebrews may here be dependent on Jewish tradition episodes from Genesis certainly pre-dates the Christian era, and is intent on presenting Abraham as a sacrificing priest ..."
Hayward, Robert Targums and the Transmission of Scripture into Judaism and Christianity (pp. 9-10) Brill, 2010