Musnad Ahmad 32:1333

'Abd al-Wahhab narrated to us, Sa'id informed us, from Qatadah, from Anas, that a man during the time of the Messenger of Allah (may Allah bless him and grant him peace) used to trade, and there was a weakness in his intellect—meaning his reasoning. His family came to the Prophet (may Allah bless him and grant him peace) and said: "O Prophet of Allah, place a restriction on so-and-so, for he trades and there is a weakness in his intellect." The Prophet of Allah (may Allah bless him and grant him peace) summoned him and forbade him from trading. He said: "O Prophet of Allah, I cannot bear to abstain from trading." He (may Allah bless him and grant him peace) said: "If you are not going to leave trading, then say: 'Take and give' (Haa' wa Haa'), and no deception."