Mukhtasar Muslim

`Sayyiduna Ibn Abbas (may Allah be pleased with them) says that` when the Messenger of Allah (peace and blessings be upon him) came to Madinah, people used to do salam (forward sale) in fruits for one or two years (i.e., they used to sell on credit). Then the Prophet (peace and blessings be upon him) said: Whoever does salam in dates should do so for a specified measure or a specified weight and for a specified period.