Musannaf Ibn Abi Shayba 9:1529

Abu Bakr narrated to us, he said: Abu Mu'awiyah narrated to us, from Mukhtar ibn Masih, from Qatadah, from Urwah ibn al-Zubayr, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Choose for your semen."