It is narrated from Hazrat Utban (may Allah be pleased with him) that I submitted in the court of Prophethood, "O Prophet of Allah, peace be upon him! I was 'engaged' with my wife when as soon as I heard your voice, I left her and immediately performed ghusl (ritual bath) and came?" The Noble Prophet, peace be upon him, said, "Ghusl becomes obligatory due to ejaculation."