Musannaf Ibn Abi Shayba 1:774

774. Abd al-Rahim ibn Sulayman narrated to us, from Zakariyya, from Abu Ishaq, from al-Harith ibn al-Azma, who said: I heard Abdullah say: "Whoever washes his head with marshmallow (khatmi) while he is in a state of major ritual impurity (junub), he has fulfilled the washing." And al-Harith said: "But he should not return what has flowed from the marshmallow onto his head again."