Tha‘labah bin Abu Sa‘ir narrates from his father that the Prophet Muhammad (peace be upon him) said:“Give one sa‘ of wheat (the narrator is unsure about one word here) on behalf of every small and great, male and female, free and slave, wealthy and poor. As for the wealthy, Allah will purify them (i.e., their wealth), and as for the poor, Allah will give them more than what they have given.”