Narrated Ibn 'Abbas: The Messenger of Allah (ﷺ) as saying: If anyone buys grain, he should not sell it until he measures it. Abu Bakr added in his version: I asked Ibn 'Abbas: Why ? He replied: Do you not see that they sell (grain) for gold, but the grain is still with the seller
SahihSahihSahih Muslim (1525)Book 24 · Hadith 81