Selected Sayings of The Holy Prophet of Islam — Page 28
The Zakaat (Spending in the Way of Allah) 36. Muaz, God be pleased with him, narrates: "Having appointed me governor (of a region), the Holy Prophet, peace and blessings of Allah be upon him, sent for me and told me: 'You will meet some People of the Book. You should invite them to bear witness that there is none worthy of worship except Allah and that I am His Messenger. If they accept this, you should let them know that Allah has made it obligatory to offer the five daily prayers. If they accept this, you should tell them that Allah has made it obligatory to give alms. These alms are taken from the rich and returned to the poor among them. If they agree to this, do not require the best of what they possess. And be mindful of the plea of the oppressed because nothing stands between this plea and Allah. " (Bukhari) 28