Musannaf Ibn Abi Shayba 1:816

Amr ibn al-Asamm al-Khuza'i narrated to us, from Ibn Budayl ibn Warqa', he said: I heard al-Qasim saying regarding the person in a state of major ritual impurity (junub) who immerses himself in water: "If he rubs his body, then it has sufficed him."