Sayyiduna Ibn Umar (may Allah be pleased with them both) narrates: When the Messenger of Allah (peace and blessings be upon him) appointed the nuqaba' (chiefs), he said: "Let no man feel anything in his heart; I only take the one whom Jibril (peace be upon him) pointed to."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13329