Musannaf Ibn Abi Shayba 13:2145

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Yunus bin Abi Ishaq narrated to us, from Mujahid, who said: He bought a dowry from a Bedouin for one hundred sa’s of dates. The Prophet, peace and blessings of Allah be upon him, said to the man: "Go and tell them to eat until they are full, and to measure out until they have received in full," meaning the measurement. The man went out while he was pulling at his elbows, meaning he was walking quickly.