Sunan Ibn Majah, Chapter: The Chapters on Business Transactions

from his father, that his grandfather Abdullah bin Salam said: "A man came to the Prophet (saw) and said, 'The tribe of Banu so-and- so, who were descended from the Jews, have become Muslim, and they are starving, and I am afraid that they may apostasize.' The Prophet (saw) said: 'Who has something with him?' A Jewish man said: 'I have such and such, and he named it, and I think he said three hundred Dinar for such and such an amount (of produce) from the garden of the tribe of Banu so-and-so.' The Messenger of Allah (saw) said: 'For such and such a price at such and such a time, but not from the garden of the tribe of Banu so-and- so."'