1. If the seller, despite knowing about the defect in the goods, conceals it from the purchaser, he will be sinful and will receive the wrath of Allah Ta‘ala and the curse of the angels.
عن عقبة بن عامر قال: سمعت رسول الله صلى الله عليه وسلم، يقول: المسلم أخو المسلم، ولا يحل لمسلم باع من أخيه بيعا فيه عيب إلا بينه له (سنن ابن ماجة رقم 2246)
Hazrat ‘Uqbah bin ‘Aamir (radhiyallahu ‘anhu) reports that Rasulullah (sallallahu ‘alaihi wasallam) said, “A Muslim is the (Deeni) brother of another Muslim, thus it is not permissible for a Muslim to sell something to his brother which has a defect in it. However, if he wishes to sell him an item that has a defect in it, he should inform him of the defect before concluding the sale.”
عن واثلة بن الأسقع قال: سمعت رسول الله صلى الله عليه وسلم، يقول: من باع عيبا لم يبينه، لم يزل في مقت الله، ولم تزل الملائكة تلعنه. (سنن ابن ماجة رقم 2247)
Hazrat Waathilah bin Asqa’ (radhiyallahu ‘anhu) reports that Rasulullah (sallallahu ‘alaihi wasallam) said, “The one who sells an item which has a defect in it without informing the purchaser of the defect, he will continue to receive the wrath of Allah Ta‘ala and the angels will continue to curse him (until he fulfils the right of his brother through compensating him or asking him forgiveness).”