Musnad Ahmad 33:775

Yahya ibn Ghaylan narrated to us, al-Mufaddal narrated to us, Yahya ibn Ayyub narrated to me, from Abd al-Rahman ibn Harmalah, from Muhammad ibn Abd Allah ibn al-Husayn, from Amr ibn Abd al-Rahman ibn Jarhad, who said: I heard a man saying to Jabir ibn Abd Allah: "Who remains with you from the companions of the Messenger of Allah, may Allah bless him and grant him peace?" He said: "Anas ibn Malik and Salamah ibn al-Akwa remain." A man said: "As for Salamah, he has apostatized from his migration." Jabir said: "Do not say that, for I heard the Messenger of Allah, may Allah bless him and grant him peace, say to [the tribe of] Aslam: 'Be Bedouins, O Aslam.'" They said: "O Messenger of Allah, we fear that we might apostatize after our migration." He said: "You are migrants wherever you may be."