Luke 10:32

(ubi sup.) Here then was man (that is, Adam) lying destitute of the aid of salvation, pierced with the wounds of his sins, whom neither Aaron the high priest passing by could advantage by his sacrifice; for it follows, And by chance there came down a certain priest that way, and when he saw him, he passed by on the other side. Nor again could his brother Moses the Levite assist him by the Law, as it follows, And likewise a Levite, when he was at the place, came and looked on him, and passed by on the other side.

(de q. Ev. l. ii. q. 19.) Or by the Priest and the Levite, two times are represented, namely, of the Law and the Prophets. By the Priest the Law is signified, by which the priesthood and sacrifices were appointed; by the Levites the prophecies of the Prophets, in whose times the law of mankind could not heal, because by the Law came the knowledge not the doing away of sin. (Serm. 171.) Or it is said, passed by, because the man who came down from Jerusalem to Jericho is believed to have been an Israelite, and the priest who came down, certainly his neighbour by birth, passed him by lying on the ground. And a Levite also came by, likewise his neighbour by birth; and he also despised him as he lay.

But He says, passed by, (Rom. 3:20; 8:3.) because the Law came and stood till its time foreordained, then, not being able to cure, departed. Mark also that the Law was not given with this previous intention that it should cure man, for man could not from the beginning receive the mystery of Christ. And therefore it is said, And by chance there came a certain priest, which expression we use with respect to those things which happen without forethought. They pitied him, I say, when they thought about him, but afterwards, overcome by selfishness, they went away again. For this is signified by the word, passed him by.