The alms the Prophet (saas) collected for the benefit of the faithful were a means whereby they were purified

at the beginning of surat at-tawba, verse 103, allah commands, "take from their wealth a charity to purify and cleanse them and pray for them." in other words, he reveals that by means of the alms he received, the prophet (saas), the beloved servant of allah, purified the faithful. the prophet (saas) is the messenger of allah, and remains on the path shown by allah in all his words and deeds. the source of the prophet (saas)'s higher morality and noble character is that he always turned to allah, without falling into the error of worshipping others besides allah. it was because he obeyed every command given by allah, he came to possess a morality and behavior of matchless quality, a model to all the world.

this truth must serve as a guide for all muslims and believers. their morality and behavior, too, must be an example to all the world, by means of their abiding by the qur'an, which is the revelation of allah, and the morality taught by the prophet (saas).

we made everything on the earth adornment for it so that we could test them to see whose actions are the best.
(surat al-kahf: 7)