According to the Halacha (Shulchan Aruch Orach Chaim 694:1), each Jew is required to send two matanos la’evyonim, charitable gifts, to at least two poverty-stricken Jews on Purim.
The Rambam (Mishneh Torah, Hilchos Megillah 2:17) points out that the more poor people one sends to, the better. In fact, he writes (ibid. 2:16) that it is better to spend more money on the gifts to the poor than on any other mitzva of Purim.
This idea is echoed in the Mishna Berura (694:3). Furthermore, as opposed to standard charitable contributions, we are to give liberally and with no investigations as to the veracity of the poor person’s claim needed.
The Chasam Sofer explains that the reason that we even give to the undeserving is because we were not entirely deserving of being saved in the Purim story.
The Klausenberger Rebbe explains that another reason for not needing to investigate is that we should not worry about where the money is going because H-Shem reversed the situation described by the Midrash (Esther Rabba 7:25) that the gentiles teasing the Jews that they would kill them and said, “we’ll take your money.” Since this fear was reversed, on Purim we should not worry where our wealth is going.
R’ Shmuel de Ozeida notes that there is a missing letter vuv in evyonim (“poverty-stricken”) to hint to this same idea that we do not need to investigate if the person is completely poor enough to be Halachically considered an evyon.
The Dena Pishra explains the inordinate focus on the poor on Purim as indicative of the fact that everyone was saved on Purim – rich and poor.
The Ben Ish Chai quotes the Midrash (Esther Rabba 7:23) that Haman mocked Pharaoh that he only killed the males (Shemos 1:16). Therefore, writes the Bein Ish Chai, the Halacha requires us to give matanos la’evyonim to two people because Haman, on the contrary, wanted to kill males and females.
The Peleh Yo’Eitz explains that this gift is meant to help the poor celebrate Purim, and not even worry about the upcoming costs of Pesach. Also, it would help strengthen the emunah of the poor, who regularly rely on the rich, and the rich rely on H-Shem.
The is similar to the anecdote when Mayer Anschel Rothchild was asked how he could shovel so much money to charity, and he famously quipped, “ G-d has a bigger shovel.”
The Gerrer Rebbe quotes the Talmud (Megillah 7b) that we are supposed to skip Torah learning and even prayer for the public reading of Megillas Esther on Purim, however chesed cannot be pushed aside. Of the three legs on which the world stands according to the Mishna (Avos 1:2), chesed cannot be removed for the world to remain.
The Alshich writes that one should mentally intend to give matanos la’evyonim in the merit of Moshe.
Rav Dan Segal notes that the mere idea that Moshe Rabbeinu requires our efforts in his honor demonstrates that we have so little idea of the heavenly impact of our actions.
To demonstrate a similar powerful idea, the Ben Ish Chai points out that the gematria of matanos (“gifts”) (40+400+50+6+400=896) is the same as manos (“gifts”) (40+50+6+400=496) and 400.
The number 400 in the Zohar (I:123b) represents evil influences. The verse uses this particular word for gifts to emphasize that giving matanos la’evyonim can provide us with the spiritual power to fight off unholy forces.