Musnad Abu Ya'la al-Mawsili 154:25

Suwayd ibn Sa'id narrated to us, Yahya narrated to us, he said: Isra'il narrated to us, from Simak, from Sa'id ibn Jubayr, from Ibn 'Umar, who said: I asked the Prophet, peace and blessings of Allah be upon him, about that. He said: "When you take one of them with the other, then do not part while there is a sale between you and him." Yahya said: And by this we take.