Musnad Ahmad 2:297

'Affan narrated to us, Shu'bah narrated to us, from al-Hakam, from Abu Wa'il, from Sabi ibn Ma'bad: That he was a Christian from the tribe of Taghlib, then he embraced Islam. He asked: "Which deed is best?" It was said to him: "Jihad in the way of Allah, the Almighty and Majestic." He wanted to perform Jihad, but it was said to him: "Have you performed Hajj?" He said: "No." It was said to him: "Perform Hajj and 'Umrah, then perform Jihad." So he entered into the state of Ihram for both of them together. He encountered Zayd ibn Suhan and Salman ibn Rabi'ah, and they said: "He is more astray than his she-camel"—or "He is not more guided than his camel." He went to 'Umar and informed him of what they had said. 'Umar said: "You have been guided to the Sunnah of your Prophet, may Allah bless him and grant him peace"—or "to the Sunnah of the Messenger of Allah, may Allah bless him and grant him peace."