Abu Siba reported,

I bought a she-camel from the house of Wathila bin Asqa. As I was leaving with her, Wathila caught up with us, dragging his cloak behind him.He said, "Abdullah, have you bought her?"I replied, "Yes."He asked, "Has the seller disclosed to you what is wrong with her?"I said, "What is wrong with her? She is plump and appears to be in good health."He asked, "Did you intend her for travel, or did you intend her for meat?"I said, "Rather, I intended to perform Hajj on her."He said, "There is a hole in her hoof."The seller protested, "May Allah set you right, why are you ruining my sale?"Wathila replied, "I heard the Messenger of Allah ﷺ say, 'It is not lawful for anyone to sell something without disclosing its defects, nor is it lawful for anyone who knows of them to keep silent about them.'"

حدثنا أبو النضر قال حدثنا أبو جعفر يعني الرازي عن يزيد بن أبي مالك قال حدثنا

أبو سباع قال

اشتريت ناقة من دار واثلة بن الأسقع فلما خرجت بها أدركنا واثلة وهو يجر رداءه فقال يا عبد الله اشتريت قلت نعم قال هل بين لك ما فيها قلت وما فيها قال إنها لسمينة ظاهرة الصحة قال فقال أردت بها سفرا أم أردت بها لحما قلت بل أردت عليها الحج قال فإن بخفها نقبا قال فقال صاحبها أصلحك الله أي هذا تفسد علي قال إني سمعت رسول الله ﷺ يقول لا يحل لأحد يبيع شيئا إلا يبين ما فيه ولا يحل لمن يعلم ذلك إلا يبينه