It is narrated from Sayyiduna Hudhayfah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) met him while he was in a state of major ritual impurity. He slipped away from him (peace and blessings be upon him) and took a bath, then came back and said: I was in a state of major ritual impurity. He (peace and blessings be upon him) said: "A believer does not become impure."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 909