Shahih Muslim - 28

Telah menceritakan kepada kami [Umayyah bin Bistham al-Aisyi] telah menceritakan kepada kami [Yazid bin Zura'i`] telah menceritakan kepada kami [Rauh] -yaitu Ibnu al-Qasim- dari [Ismail bin Umayyah] dari [Yahya bin Abdullah bin Shaifi] dari [Abu Ma'bad] dari [Ibnu Abbas] bahwa Rasulullah shallallahu 'alaihi wasallam ketika mengutus Mu'adz ke Yaman, beliau bersabda: "Sesungguhnya kamu menghadapi suatu kaum Ahli Kitab, maka hendakah pertama kali yang kalian dakwahkan kepada mereka adalah penyembahan kepada Allah azza wa jalla, apabila mereka mengenal Allah, maka beritahukanlah bahwa Allah mewajibkan kepada mereka shalat lima waktu pada siang dan malam mereka, apabila mereka melakukannya maka beritahukanlah kepada mereka bahwa Allah telah mewajibkan zakat atas mereka yang diambil dari orang kaya mereka lalu dibagikan kepada orang fakir mereka. Jika mereka menaatimu dengan hal tersebut, maka ambillah zakat dari mereka dan takutlah dari harta mulia mereka." (HR. Muslim: 28)

It is narrated on the authority of Ibn 'Abbas that when the Messenger of Allah (may peace be upon him) sent Mu'adh towards Yemen (as governor) he said to him: Verily you would reach a community of the people of the Book, the very first thing to which you should call them is the worship of Allah, may His Glory be Magnificent, and when they become fully aware of Allah, instruct them that He has enjoined five prayers on them during the day and the night, and when the begin observing it, then instruct them that verily Allah has made Zakat obligatory for them which would be collected from the wealthy amongst them and distributed to their needy ones, and when they submit to it, then collect it from them and avoid (the temptation) of selecting the best (items) of their riches. (Muslim: 28)