I have talked a couple of times on this blog about the allegorical interpretation of this parable (by Irenaeus and Clement) but to remind you of the gist of this interpretation, let me paste a quote from Augustine's famous interpretation of the parable to put the above description into context. Augustine’s interpretation follows those by Irenaeus, Origen, and Ambrose, and others, who all see the Samaritan as symbolizing Christ healing the wounds caused by sin and who detect numerous other allegorical details in the parable.
A certain man went down from Jerusalem to Jericho; Adam himself is meant; Jerusalem is the heavenly city of peace, from whose blessedness Adam fell; Jericho means the moon, and signifies our mortality, because it is born, waxes, wanes, an dies. Thieves are the devil and his angels. Who stripped him, namely; of his immortality; and beat him, by persuading him to sin; and left him half-dead, because in so far as man can understand and know God, he lives, but in so far as he is wasted and oppressed by sin, he is dead; he is therefore called half-dead. The priest and the Levite who saw him and passed by, signify the priesthood and ministry of the Old Testament which could profit nothing for salvation. Samaritan means Guardian, and therefore the Lord Himself is signified by this name. The binding of the wounds is the restraint of sin. Oil is the comfort of good hope; wine the exhortation to work with fervent spirit. The beast is the flesh in which He deigned to come to us. The being set upon the beast is belief in the incarnation of Christ. The inn is the Church, where travelers returning to their heavenly country are refreshed after pilgrimage. The morrow is after the resurrection of the Lord. The two pence are either the two precepts of love, or the promise of this life and of that which is to come. The innkeeper is the Apostle. The supererogatory payment is either his counsel of celibacy, or the fact that he worked with his own hands lest he should be a burden to any of the weaker brethren when the Gospel was new, though it was lawful for him “to live by the gospel” (Dodd 1961: 1-2; slightly abridged).