Amr bin al-Rabi' narrated the like of it with the same chain. Aqil added these words: The Messenger of Allah (peace and blessings be upon him) said: "Is there not in water and acacia bark what would purify it, or tanning?"
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 65