How better could one honor St. Martin's day than by living it in that spirit of his? Martin gave away half his cloak: we can go through our wardrobe and select any clothes that are at all superfluous--if we would really resemble Martin we should give more than what can be spared--and we can immediately send or give it to someone in need, either directly, or indirectly through some organization. It is important to remember, though, that Martin gave the cloak he was actually wearing, that is to say, something that was fit to be worn. The idea is not to give away merely old clothes, but garments in such condition that we ourselves would be willing to wear them. After all, when Martin saw his cloak, not on the beggar but on Christ himself, it was reality that he saw. Any clothes, any single thing that we give to another person we are giving to Christ.
Source: A Candle is Lighted, 1945