Tawus said that he heard Sayyiduna Ibn Abbas (may Allah be pleased with them both) (say) that the Messenger of Allah (peace and blessings be upon him) said regarding food: "It should not be sold before possession is taken of it." Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: I think that all things are like it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10680