What was the advice given by Abdullah bin Salam to Abu Burda when Abu Burda arrived in Medina concerning accepting presents of chopped straw, barley or other items that may be owed to him? (peace be upon him)
 Narrated Abu Burda:                     When I came to Medina. I met `Abdullah bin Salam. He said, "Will you come to me so that I may serve you with Sawiq (i.e. powdered barley) and dates, and let you enter a (blessed) house that in which the Prophet entered?" Then he added, "You are In a country where the practice of Riba (i.e. usury) is prevalent; so if somebody owe you something and he sends you a present of a load of chopped straw or a load of barley or a load of provender then do not take it, as it is Riba."