The Constitution of Medina, also known as the Charter of Medina, was drafted in 622. It concerns the rights and responsibilities of the Muslim, Jewish, and other Arab and tribal communities of Medina during the war between that city and its neighbours. Legal Scholar L. Ali Khan explains that the Constitution of Medina was a social contract derived from a treaty and not from any fictional state of nature or from behind the Rawlsian veil of ignorance. The contract was built upon the concept of one community of diverse tribes living under the sovereignty of One God. The Medina Constitution also instituted peaceful methods of dispute resolution among diverse groups living as one people but without assimilating into one religion, language, or culture. [1]

Important points

The most important points with respect to the geographically close Arab tribes, Muslim and Jewish, in the immediate area of Medina:

1. The Jews will profess their religion, and the Muslims theirs.
2. The Jews shall be responsible for their expenditure, and the Muslims for theirs.
3. If attacked by a third party, each shall come to the assistance of the other.
4. Each party shall hold counsel with the other. Mutual relation shall be founded on righteousness; sin is totally excluded.
5. Neither shall commit sins to the prejudice of the other.
6. The wronged party shall be aided.
7. The Jews shall contribute to the cost of war so long as they are fighting alongside the believers.
8. Medina shall remain sacred and inviolable for all that join this treaty. Should any disagreement arise between the signatories to this treaty, then Muhammad shall settle the dispute.
9. The signatories to this treaty shall boycott Quraish commercially; they shall also abstain from extending any support to them.
10. Each shall contribute to defending Medina, in case of a foreign attack, in its respective area.
11. This treaty shall not hinder either party from seeking lawful revenge.

http://en.wikipedia.org/wiki/Constitution_of_Medina