Ramazim for Tzedakah and the Half Shekel
For every mitzvah a person receives reward in the world to come. However with the mitzvah of tzedakah a person can merit reward in this world as well, as it says “Aser ta’aser”, upon which Chazal expound, “Give your tithes in order to acquire wealth.’

                 The Gemara says that a person who gives tzedakah is greater than Moshe Rabeinu. But would we think that Moshe did not give tzedakah? Rather,  the generation of Moshe, who ate from the heavenly mon, did not need to be sustained like the poor in our generation. Therefore, Moshe could not perform the mitzvah of tzedakah at a level that we can. (R’ Chaim Velozhin)
”And he will give an atonement for his soul.” The trope on the word v’nasnu “and they will give” is a kadma v’azla (literally precede and go) which hints to the statement  “One should present the poor with bread…for it is a wheel which returns in this world.” The word v’nasnu “and they will give” can be read both forwards  and backwards, for sometimes the one who gives might also one day need to receive. This is hinted in the trope, for one can precede to give and then it will come back in return. (Aderes Eliyahu Shemos 30:12)The commentaries ask why a half shekel and not a whole shekel? Would something done in a complete manner be more fitting? The word machtzis, half, begins and ends with a mem and suf, the letters which mean death. The next letters, ches and yud, spell life. The middle letter is tzadi, which stand for tzedakah. This hints that tzedakah pushes off death and brings close life
Pinchas risked his life to take vengeance for Hashem when he killed Zimri. There is no greater tzedakah than this, for the verse says, “And he returned my wrath,chamasi, which could also mean that he reversed the letters of chamasi. The word has the letters which mean death close to each other while the letters for life are separated. By performing his act of tzedakah he brought life to Klal Yisrael. (Kol Eliyahu)