Musannaf Ibn Abi Shaybah 22123 — Buyer and seller who differ

Al-Sha'bi (may Allah have mercy on him) said: If the seller and the buyer disagree and neither has witnesses, and the item sold remains in its original state, the word of the seller is accepted, or else the sale is annulled. If the item sold has perished, the word of the buyer is accepted, and the seller must produce witnesses.