Musnad Abu Ya'la al-Mawsili 2:106

Abu Khaythama, Harun ibn Ma'ruf, and others narrated to us, they said: 'Abdullah ibn Yazid al-Muqri' narrated to us, Sa'id ibn Abi Ayyub narrated to us, from 'Ata' ibn Dinar, from Hakim ibn Sharik, from Yahya ibn Maymun al-Hadrami, from Rabi'ah al-Jurashi, from Abu Hurayrah, from 'Umar ibn al-Khattab, who said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: "Do not sit with the people of Qadar (those who deny divine decree), and do not initiate conversation with them."