Hazrat Sha'bi says that Hazrat Shurayh used to administer an oath regarding that illness which cannot be seen, based on its knowledge and its apparent signs.

Hazrat Salim narrates that Hazrat Ibn Umar (may Allah be pleased with them both) sold a slave for eight hundred dirhams. Later, the buyer found a defect in him and brought the case before Hazrat Uthman (may Allah be pleased with him). Hazrat Uthman (may Allah be pleased with him) asked Hazrat Ibn Umar (may Allah be pleased with them both) about this matter. He replied that he had sold him with a declaration of exemption from defects. Hazrat Uthman (may Allah be pleased with him) then said to Hazrat Ibn Umar (may Allah be pleased with them both): "Do you swear that at the time you sold him, you had no knowledge of any defect in him?"

Hazrat Ata says that if a person buys some goods and then finds a defect in them, the buyer will need to provide testimony that this defect was present while the goods were with the seller. If testimony is provided, then fine; otherwise, the seller will be made to swear an oath that he was not aware of the defect. Hazrat Amr bin Dinar says that the oath should be regarding knowledge.

Hazrat Aamir says that if a man bought a slave-girl and then found that she had smallpox, and the buyer had no witnesses, then the seller will be made to swear an oath that when he sold her, she did not have smallpox.

Hazrat Umar bin Zar states that Hazrat Qasim bin Abdur Rahman used to swear that when the seller handed over the item, he was not aware of its defect. Hazrat Sha’bi, regarding the "Yameen Mursalah" (unrestricted oath), states that its sin is upon the one who knowingly swears a false oath.

22077 - Al-Sha'bi said regarding the unqualified oath: Its sin and its righteousness are only according to what is intended.

Hazrat Ata Madani says that a man sold some goods, then the buyer claimed there was a defect, and they brought this dispute to Hazrat Uthman bin Affan (may Allah be pleased with him). The buyer said, "Swear by Allah that when you sold it to me, there was no defect in it." The seller said, "I swear that when I sold this thing to you, I had no knowledge of any defect in it." Hazrat Uthman (may Allah be pleased with him) said, "This man has done justice to you."

Hazrat Zubair bin Junadah says that I asked Hazrat Salim whether I can buy barren land subject to kharaj for cultivation. He replied that there is no harm in it. I asked whether its kharaj will be paid. He replied that there is no harm in it. I said that I make an agreement for the minors. He said that this matter is in the minds of men.