The Prophet (ﷺ) came to Medina and the people used to pay in advance the price of dates to be deliveredwithin two or three years. He said (to them), "Whoever pays in advance the price of a thing to bedelivered later should pay it for a specified measure at specified weight for a specified period."as above, saying, "He should pay the price in advance for a specified measure and for a specifiedperiod."