Mishkat al-Masabih 2833
Abu Burda b. Abu Musa said:
I came to Medina and met 'Abdallah b. Salam who said, "You are in a land in which usury is common, so when anyone owes you anything and presents you with a load of straw, or a load of barley, or a rope of lucerne grass, do not accept it for it is usury." 

Bukhari transmitted it.
وَعَنْ أَبِي بُرْدَةَ بْنِ أَبِي مُوسَى قَالَ: قدمت الْمَدِينَة فَلَقِيت عبد الله بن سلا م فَقَالَ: إِنَّك بِأَرْض فِيهَا الرِّبَا فَاش إِذا كَانَ لَكَ عَلَى رَجُلٍ حَقٌّ فَأَهْدَى إِلَيْكَ حِمْلَ تَبْنٍ أَو حِملَ شعيرِ أَو حَبْلَ قَتٍّ فَلَا تَأْخُذْهُ فَإِنَّهُ رِبًا. رَوَاهُ الْبُخَارِيُّ