3 And if you think this a great thing, wait, and you will see clearly, that neither yet have you attained to perfection. For not even here does He stop with you, who is laying down the laws of patient endurance, but He proceeds even further, thus saying,
“If any one shall compel you to go one mile, go with him two.”
Do you see the height of self-denial? In this at least, that after giving your coat, and your cloak, not even if your enemy should wish to use your naked body for hardships and labors, not even so (says He), must thou forbid him. For He would have us possess all things in common, both our bodies and our goods, as with them that are in need, so with them that insult us: for the latter comes of manliness, the former of mercifulness.
Because of this, He said, “If any one shall compel you to go one mile, go with him two:” again leading you higher up, and commanding you to show forth the same kind of ambition.
For if the things of which He spoke at the beginning, being far less than these, have so great blessings pronounced on them; consider what sort of portion awaits them, who duly perform these, and what they become even before their rewards, in a human and passible body winning entire freedom from passion. Since when neither insult, nor blows, nor the spoiling of their property, galls them; while they give way to no such thing, but rather add in large measure to their endurance; reflect what kind of training their soul is undergoing.
On this account then, as in regard of blows, as in regard of our goods, so in this case also, He has bidden us act. “For why,” says He, “do I mention insult, and property? Though he should want to make use of your very own limbs for toil and weary work, and this unjustly, do thou again conquer and overpass His unjust desire.”
For “to compel” is this, to drag unjustly and without any reason, and by way of despite. Nevertheless, for this also be thou ready in your station, so as to suffer more than the other would fain do to you.
“Give to him that asks you, and from him that would borrow of you, turn not thou away.”
These last are less than what went before; but marvel not, for this He is ever wont to do, mingling the small with the great. And if these be little in comparison with those, let them hearken, who take the goods of others, who distribute their own among harlots, and kindle to themselves a double fire, both by the unrighteous income, and by the pernicious outlay.
But by “borrowing,” here, He means not the compact with usury, but the use merely. And elsewhere He even amplifies it, saying that we should give to them, from whom we do not expect to receive.
Source: Homilies on the Gospel of St. Matthew (New Advent)