It was narrated that 'Uqbah bin 'Amir said:
"I heard the Messenger of Allah (ﷺ) say: 'The Muslim is the brother of another Muslim, and it is not permissible for a Muslim to sell his brother goods in which there is a defect, without pointing that out to him."' (PT)
English reference (PT): Vol. 3, Book 12, Hadith 2246 (PT)
Arabic reference (PT): Book 12, Hadith 2331 (PT)