Hebrews 7:8

"And here men that die receive tithes: but there he of whom it is testified that he liveth." But lest we should say, Tell us, why goest thou so far back? He says, "And as I may so say" (and he did well in softening it) "Levi also who receiveth tithes payed tithes in Abraham." How? "For he was yet in his loins when Melchisedec met him," i.e. Levi was in him, although he was not yet born. And he said not the Levites but Levi. Hast thou seen the superiority? Hast thou seen how great is the interval between Abraham and Melchisedec, who bears the type of our High Priest? And he shows that the superiority had been caused by authority, not necessity. For the one paid the tithe, which indicates the priest: the other gave the blessing, which indicates the superior. This superiority passes on also to the descendants.

It shows that there was great excellence in Melchizedek, and therefore he received tithes, and it says: Even the Levites receive; but this is not great, for they die; who, then, envies the honor of one who is about to die? However, Melchizedek, even if he received testimony that he lives, received tithes. And what it says about him receiving testimony that he lives, take according to the previously given understanding, namely because Scripture did not say the end of him, but only life, it seemed to testify only that he lived; as if to say: Abraham foresaw that the death of Melchizedek would not be revealed, nor was he moved to envy him the honor of tithes, for he knew his dignity.For he has superiority. The simpler way to accept what is said is that the priesthood of the Levites dies. For it has ceased. The truths have been revealed; but the one of Melchizedek lives. "that he lives." How then was he testified? In saying to God, "You are a priest forever according to the order of Melchizedek." (Heb. 7:17) And therefore, the distinction of Melchizedek from the priests among the Jews. "the men who die." For he says, it is not to be assumed that at any time he became greater, but after this he was established in a lesser portion. For in the law, the Levites receive tithes, and those who die pass on their value to others. So that the same ones are not always those who receive the tithe. But here, we have learned nothing of the sort. Therefore, he should always be regarded as superior, if indeed he remains always upon his own value. For he remains, as I said, an everlasting priest, having taken this from Scripture, as in the saying, "You are a priest forever according to the order of Melchizedek," (Heb. 7:17) showing that he is such an everlasting priest.