question #1 Sahih al-Bukhari 2414, Book 44, Hadith 5 : What guidance did the Prophet Muhammad (ﷺ) provide to someone who was frequently cheated in transactions?

A man was often cheated in buying. The Prophet (ﷺ) said to him, “When you buy something, say (to the
seller), No cheating.” The man used to say so thenceforward .