A thought from R. Tzadok of Lublin:
The mitzvah of Matanot L’evyonim is that one should give indiscriminately, as expressed in Rambam (Mishna Torah, Laws of Megilla 2:8): “We should not be discriminating in selecting the recipients of these Purim gifts. Instead, one should give to whomever stretches out his hand.”
When we give in this manner towards our fellow man, G-d reciprocates in kind; He bestows G-dly sustenance on each and every individual.
As long as we stretch out our hands in request for His assistance, G-d will give us.
The true destitute is the Jew whose soul thirsts for G-d’s salvation.
Although he is poor in the Talmudic sense that (Nedarim 41a) “no one is poor save he who lacks knowledge,” nevertheless when G-d provides for him, He gives in a way that befits a king – the Jew then becomes full with all that is good and holy.
(Machshevet Charutz pg. 121)