(8) باب بُطْلاَنِ بَيْعِ الْمَبِيعِ قَبْلَ الْقَبْضِ
Ibn Abbas (Allah be pleased with them) reported Allah's Messenger (ﷺ) as saying:
He who buys foodgrain should not sell it, until he has weighed it (and then taken possession of it). I (Tawus) said to Ibn Abbas (Allah be pleased with them): Why is it so? Thereupon he said: Don't you see that they (the people) sell foodgrains against gold for the stipulated time. Abu Kuraib did not make any mention of the stipulated time.
Reference: Sahih Muslim 1525 d
In-book reference: Book 21, Hadith 39
USC-MSA web (English) reference(deprecated numbering scheme): Book 10, Hadith 3643