Sahih Muslim 64a

Muhammad ibn Bakkar ibn al-Rayyan and Awn ibn Sallam narrated to us; they said: Muhammad ibn Talhah narrated to us. (Another chain:) Muhammad ibn al-Muthanna narrated to us; Abd al-Rahman ibn Mahdi narrated to us; Sufyan narrated to us. (Another chain:) Muhammad ibn al-Muthanna narrated to us; Muhammad ibn Ja'far narrated to us; Shu'bah narrated to us. All of them reported from Zubayd, from Abu Wa'il, from Abdullah ibn Mas'ud, who said: The Messenger of Allah (peace and blessings be upon him) said: ‘Abusing a Muslim is sinful disobedience, and fighting him is disbelief.’ Zubayd said: I asked Abu Wa'il, ‘Did you hear it from Abdullah, narrating it from the Messenger of Allah (peace and blessings be upon him)?’ He said: ‘Yes.’ Shu'bah's narration does not include Zubayd's question to Abu Wa'il.