This man is interpreted as Adam, who stands for mankind. Jerusalem is that heavenly city of peace from whose blessedness he has fallen, and from which he has come down to this mortal and unhappy life.
And well does Jericho, which is interpreted as the moon, stand for this ever-changing present life, since like the moon it is ever uncertain in its wanderings and in its changes.
And fell among robbers.
Here for robbers understand the devil and his angels, among whom, as he came down, he fell.
For had he not first through pride grown big within him, he would not have so easily fallen when tempted from without. True indeed are the words: The spirit is uplifted before a fall (Prov. xvi. i8).
Who also stripped him.
They deprived him of the glory of the garment of immortality and innocence.
For this is that first robe with which, according to another parable, the prodigal son, returning through repentance (Lk. xv. 22), was adorned, and, having lost it, our first parents saw themselves as naked, and put on the skin garments of a nature now mortal.
And having wounded him went away, leaving him half dead.
The wounds are sins, by means of which they implanted in his weakened body a sort of seedbed (if I may say so) of growing death, profaning the integrity of human nature.
They went away, but not as ceasing from their assaults, but to conceal their attacks by craft.
They left him half dead; for though they were able to strip him of the blessedness of immortal life, they were not able to deprive him of the power of reason.
For in that part of him in which he can taste and know God, man is alive. But in the part that is grown weak from sin and faints from wretchedness, he is dead; defiled by a mortal wound.
And it chanced that a certain priest went down the same way; and, seeing him, passed by. In like manner also a Levite, when he was near the place and saw him, passed by.
The Priest and the Levite, who seeing the wounded man passed by, signify the priesthood and ministry of the Old Testament, when the wounds of the clean sick could only be pointed out by the decrees of the Law, but could not be cured by them.
For it was impossible (as the Apostle says) that by the blood of calves and lambs or by the blood of goats, sin should be taken away (Heb. x. 4).
The Venerable Bede (672/4-735):Commentary on St Luke’s Gospel (PL 92, Lib. III, Cap. X, col. 467); Translated by M.F. Toale, D.D. @ Lectionary Central.