The Messenger of Allah ﷺ said, "None of you should sell over the sale of another."
أن رسول الله ﷺ قال: لا يبع بعضكم على بيع بعض.
No references are available.
Malik narrated it in "Buyu" (95) from Nafi, from Abdullah bin Umar. Bukhari narrated it in "Buyu" (2139), and Muslim in "Buyu" (1412), through the route of Malik, with the same wording. Abu Dawud added, "unless he permits him." And the wording of Nasai is, "... until he buys or leaves it."