It is narrated from Sayyiduna Wathilah bin al-Asqa' (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The imam is a guarantor and the mu'adhdhin is entrusted. O Allah, forgive the mu'adhdhins and guide the imams."
Hadith Referenceالمعجم الكبير للطبراني / باب الواو / 18423