Musnad Ahmad 5:557

Abdullah narrated to us, Ibrahim ibn al-Hajjaj al-Naji and Muhammad ibn Aban ibn Imran al-Wasiti narrated to us, they said: Hammad ibn Salamah narrated to us—and this is the wording of Muhammad ibn Aban—from Ata ibn al-Sa’ib, from Zadhan, from Ali, who said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: "Whoever leaves a place of a hair from [the state of] janabah (major ritual impurity) without water touching it, such and such will be done to him of the Fire." Ali said: "Because of that, I became hostile toward my hair, as you see."