When Mohammed peace be and blessings upon him came to Medinah, he found himself confronted with many problems, internal as well as external. He was faced with aggression from the Quraysh and subversion and revolt from the hypocrites and the Jews of Medinah. Shortly thereafter, the Prophet peace be and blessings upon him got a written document, which bound the Muhaajirun and the Ansaars to a friendly agreement. The covenant made the Jews a party to the treaty that guaranteed them the freedom of their rights and obligations.
(Ibn Hisham, Vol. p. 501).
He made pacts and treaties of diverse natures with the Jews, but the most significant agreement which the Prophet peace be and blessings upon him signed was with the Jews of Medinah.