It is narrated from Sayyiduna Abu Bakrah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) entered the Fajr prayer and gestured with his hand: "Stay in your places." Then he (peace and blessings be upon him) came back with drops of water falling from his head, and then he (peace and blessings be upon him) led them in prayer. When he (peace and blessings be upon him) completed the prayer, he said: "I am only a human being, and I was in a state of major ritual impurity (janabah)."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4063