"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."' (Using translation from Ibn Mājah 2246)
سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ الْمُسْلِمُ أَخُو الْمُسْلِمِ وَلَا يَحِلُّ لِمُسْلِمٍ إِنْ بَاعَ مِنْ أَخِيهِ بَيْعًا فِيهِ عَيْبٌ أَنْ لَا يُبَيِّنَهُ لَهُ