Musannaf Ibn Abi Shayba 33:528

Waki’ narrated to us, from Isma’il, from Qays, from Jarir, that he said to his people while he was admonishing them: "You are nothing but like the ostrich that hides itself, and they take a back [to hide behind]. If you do not find a back, then [it is] upon you. Indeed, the first of the earth to be ruined is its left side, then its right side will follow it. The place of gathering is here, and I am following in the tracks."