Musannaf Ibn Abi Shayba 9:1279

Abu Bakr narrated to us, he said: Ibn ‘Ulayyah and Marwan bin Mu’awiyah narrated to us, from Ma’mar, from al-Zuhri, from Salim, from Ibn ‘Umar, he said: Ghilan bin Muslim al-Thaqafi accepted Islam, and he had ten wives under him. The Messenger of Allah (may Allah bless him and grant him peace) said: "Take four from among them."