Narrated to us my father : Narrated to us Ahmad bin Idrees: Narrated to us Ahmad bin Muhammad bin Isa from Ahmad bin Muhammad bin Abi Nasr from Hammad bin Uthman from Abdullah bin Abi Yafur that he asked Aba Abdillah : “Can the earth remain without an Imam?” He replied: “No.” Then he was asked, “Can there be two Imams at one and the same time?” “No,” he replied, “Except that one of them is silent (and he does not announce his Imamate).”