Musnad Ahmad 30:185

Sufyan narrated to us, from Abu al-Zinad, from al-A'raj, from Abu Hurairah, attributing it [to the Prophet], and he said once: He said: The Messenger of Allah, may Allah bless him and grant him peace, said: "My heirs shall not divide a dinar nor a dirham. Whatever I leave behind, after the maintenance of my wives and the provision of my worker, is charity."