Why were there Jews in Madeenah at the time of the Prophet?
Question

                It was narrated that when the Prophet (peace and blessings of Allaah be upon him) died, his shield was in pledge with a Jew… My question is: was this Jew in Madeenah? If the answer is yes, then how could that be when he (peace and blessings of Allaah be upon him) had expelled them from the city?
Praise be to Allah.
    When the Prophet  (peace and blessings of Allaah be upon 
    him) died, his shield was in pledge with a Jew. The Prophet  (peace and 
    blessings of Allaah be upon him) had expelled some of the Jews, and he left 
    orders during his final illness that they should be expelled from the 
    Arabian Peninsula, and that no two religions should co-exist there. Then 
    ‘Umar (may Allaah be pleased with him) carried out this final wish of the 
    Prophet  (peace and blessings of Allaah be upon him).