Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates: When the Noble Prophet (peace and blessings be upon him) arrived in Madinah, people used to conduct forward sales (salam) for one or two years. So he said:“Whoever wants to do a forward sale (salam), let him do so for a specified measure and a specified weight for a specified period.”These are the words of the narrator named Nishapuri. Muhali has narrated these words: They used to do forward sales regarding grain, dates, or date palms, so the Prophet said:“Do it for a specified period and sell a measured quantity.”