The Messenger of Allaah's (SAAS) Letter to al-Hilaal
Peace be to you; I praise to you God, beside whom there is no god, and who has no partner; and I summon you to God alone, that you believe in God, and obey, and enter into the community (Jam'aah). That is better for you. Peace be upon whoever follows the guidance.
This is a letter of Muhammad the Prophet, the Messenger of God, to the people of Najran. To him belong the decision in respect of every fruit, and every slave; but he was gracious to them and left (them) all that for the payment of 2,000 suits of clothes (yearly), each suit worth one ounce (of silver). Where these tribute-suits exceed or fall short of the ounce, that is taken into account. Whatever was taken from them of the coats of mail and horses and riding camels and equipment they possessed is taken into account. Najran is to give lodging to my messengers for twenty days or less (and) to lend thirty coats of mail, thirty horses, and thirty camels if there is a war (kayd) in Yemen. Whatever is destroyed of the coats of mail or horses or camels they lend my members is guaranteed by my messengers until they repay it.
Najran and their followers have protection (jiwar) of God and the dhimma of Muhammed the Prophet the Messenger of God, for themselves, their community, their land and their goods, both those who are absent and those who are present, and for their churches and their services (no bishop will be moved from his episcopate, and no monk from his monastic position, and no church warden from his church wardenship) and for all, great or little, that is under their hands. There is no usury and no blood revenge from pre Islamic times.
If any of them ask for a right, justice is (in their own hands, to see that they are) not doing wrong and not suffering wrong; it belongs to Najran. If any one takes usury after this, my dhimma is free from (responsibility for) him. No one of them is punished for the wrongdoing of another. On the terms stated in this document (they have) protection of God and dhimma of the Prophet forever, until God comes with His command, if they are loyal and perform their obligations well, not being burdened with wrong.