Simak narrates from Sayyiduna Jabir bin Samurah (may Allah be pleased with him): I heard the Prophet (peace and blessings be upon him) say: "There will be twelve leaders (amirs)." Then he (peace and blessings be upon him) said something I could not understand, so the people said: He (peace and blessings be upon him) said: "All of them will be from Quraysh."
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 1883