Selling that which is defective is not permissible

Question :

I am a vegetable merchant and I have a partner who bought 40 Qintaar of pears from a distance of 1,000 km. Then, when selling these pears to the smaller businessmen it was found that the pears were bad, as all of them had worms in them and all of them were not fit for eating. This is while knowing that I am the one who sold them to the smaller businessmen and I did not know that they had worms in them and that they were not fit for eating. In reference to my partner who brought these pears, he knew they were bad, when he arrived at his place and he did not inform me that all of the pears were bad. All he said to me was that a few of them had worms in them. So, what is the ruling of the Islamic law concerning this sale? And what is the ruling concerning the smaller businessmen who knew that the pears were bad and then sold them anyway?

Answer:

Selling a defective product without clarifying its defect (to the buyer) is not permissible as it is a form of deception, about which the Messenger of Allâh said:
"Whoever deceives us, then he is not of us."

And it has been confirmed from him that he said:
"The two people involved in a sales transaction have the choice (of going through with it) as long as they do not separate from each other. If they were truthful and they made things clear, they will be blessed in their sale, and if they concealed anything and lied, the blessing of their sale is eradicated."

Whoever deceived and sold a defective product at the price of a good product must repent to Allâh, feel guilty for what he did and not repeat that act again. Also, he must seek the pardon of whoever he cheated and rectify matters with him by returning to him what he deserves.

Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 4 Pages 437-438