Abu Sa'id al-Khudri reported God’s Messenger as saying, “If anyone pays in advance for an article he may not transfer, it to someone else before he receives it.”
‘Umar reported the Prophet as saying, “He who brings goods for sale is blessed with good fortune, but he who keeps them till the price rises is accursed.”
Ibn ‘Abbas reported God’s Messenger as saying to those who measured commodities by capacity and those who measured by weight, “You have been put in charge of two matters because of which peoples of the past before your time perished.”