Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates: The Prophet (peace and blessings be upon him) took forty sa' of dates as a loan from a man of the Ansar. That Ansari fell into need and came to the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) said: "Nothing has come to us since then." The man intended to say something, but the Prophet (peace and blessings be upon him) said: "Say only what is good, for I am the best of those who borrow." Then the Prophet (peace and blessings be upon him) gave him forty sa' extra and returned forty sa' for his loan, so he gave him eighty sa'.
Al-Bazzar recorded it, and its narrators are the narrators of the Sahih, except al-Bazzar's teacher, who is thiqah (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب البيوع / 6690