Strengthening a Jew who is confronted with economic challenges is a practical mitzvah. After all, if we ignore our brother’s plight, what good is our personal frumkeit, religious observance? A Jew whose observance is predicated upon his relationship with Hashem, while he simultaneously ignores the challenges that his brother must confront, is deluding himself. We are all one family. One cannot expect his brother to derive satisfaction from one son, when that very same son ignores the adversity suffered by his own brother.
There is yet a deeper understanding of the mitzvah of supporting a fellow Jew who has come on hard times. As noted by the Bais HaLevi, when one supports the poor he fulfills a number of mitzvos. As a result, the ani, poor man, becomes a cheftza shel mitzvah, the vehicle through which the mitzvah is performed. During those moments that he asks for and receives alms, he is very much like an Esrog, Lulav, Shofar, etc., The mitzvah is being performed through him.
When Succos is over and we no longer require the services of the Succah or Four Species, they no longer retain the kedushah, sanctity, which had been infused them during the Festival. The Succah’s sanctity is the result of its connection with the Yom Tov. Once the Festival has concluded, so, too, does the Succah’s kedushah. The poor man retains his kedushah throughout the tzedakah dialogue. Thus, just as it is prohibited to cover the blood of a slaughtered fowl (kisui ha’dam) using one’s foot, because it is not respectful (being that the blood of kisui ha’dam is a cheftza shel mitzvah), so, too, it is forbidden to be lax in extending our utmost respect to the poor man who stands before us. After all, he is a cheftza shel mitzvah.