Musannaf Ibn Abi Shayba 13:850

Abu Bakr narrated to us, he said: Ad-Dahhak ibn Makhlad narrated to us, from Ibn Jurayj, from ‘Ata’, regarding a man who buys goods or merchandise, then a defect appears in it. He said: The buyer seeks evidence that it was [present] with the seller. If he finds [it], then [it is as it is]; otherwise, the seller is made to swear an oath regarding his knowledge. And ‘Amr ibn Dinar said: He swears an oath regarding his knowledge.