Musannaf Ibn Abi Shaybah 774 — A man performing his ghusl for janabah

Abd al-Rahman bin Harmalah said: A man from my family performed the ritual bath for janabah but forgot to wash his head. He told me to ask Sa'id bin al-Musayyib about the matter. I asked him, and he said: "Let him go back and wash his head." So I went and poured water for him from the ablution water until he had washed his head.