Musnad Ahmad 27:1957

'Abd al-Samad narrated to us, Sakhr narrated to us, from Nafi', from Ibn 'Umar, who said: "The Messenger of Allah (may Allah bless him and grant him peace) forbade that a resident should sell for a bedouin." And he used to say: "Do not meet the goods (before they reach the market), and let not some of you sell over the sale of others, and let not one of you propose to a woman who has already been proposed to by his brother, until the first suitor leaves it, or he gives him permission, so he may propose."