Mystically, the heifer taken from the herd signifies the flesh of Christ; which had not drawn a yoke, since it had done no sin; nor did it plough the ground, i.e. it never knew the stain of revolt.  The fact of the heifer being killed in an uncultivated valley signified the despised death of Christ, whereby all sins are washed away, and the devil is shown to be the arch-murderer. ________________________

THIRD ARTICLE [I-II, Q. 105, Art. 3]

Whether the Judicial Precepts Regarding Foreigners Were Framed in a
Suitable Manner?

Objection 1:  It would seem that the judicial precepts regarding foreigners were not suitably framed.  For Peter said (Acts 10:34, 35):  “In very deed I perceive that God is not a respecter of persons, but in every nation, he that feareth Him and worketh justice is acceptable to Him.”  But those who are acceptable to God should not be excluded from the Church of God.  Therefore it is unsuitably commanded (Deut. 23:3) that “the Ammonite and the Moabite, even after the tenth generation, shall not enter into the church of the Lord for ever”:  whereas, on the other hand, it is prescribed (Deut. 23:7) to be observed with regard to certain other nations:  “Thou shalt not abhor the Edomite, because he is thy brother; nor the Egyptian because thou wast a stranger in his land.”

Obj. 2:  Further, we do not deserve to be punished for those things which are not in our power.  But it is not in man’s power to be an eunuch, or born of a prostitute.  Therefore it is unsuitably commanded (Deut. 23:1, 2) that “an eunuch and one born of a prostitute shalt not enter into the church of the Lord.”

Obj. 3:  Further, the Old Law mercifully forbade strangers to be molested:  for it is written (Ex. 22:21):  “Thou shalt not molest a stranger, nor afflict him; for yourselves also were strangers in the land of Egypt”:  and (Ex. 23:9):  “Thou shalt not molest a stranger, for you know the hearts of strangers, for you also were strangers in the land of Egypt.”  But it is an affliction to be burdened with usury.  Therefore the Law unsuitably permitted them (Deut. 23:19, 20) to lend money to the stranger for usury.

Obj. 4:  Further, men are much more akin to us than trees.  But we should show greater care and love for those things that are nearest to us, according to Ecclus. 13:19:  “Every beast loveth its like:  so also every man him that is nearest to himself.”  Therefore the Lord unsuitably commanded (Deut. 20:13-19) that all the inhabitants of a captured hostile city were to be slain, but that the fruit-trees should not be cut down.

Obj. 5:  Further, every one should prefer the common good of virtue to the good of the individual.  But the common good is sought in a war which men fight against their enemies.  Therefore it is unsuitably commanded (Deut. 20:5-7) that certain men should be sent home, for instance a man that had built a new house, or who had planted a vineyard, or who had married a wife.