Musannaf Ibn Abi Shayba 1:1471

Ibn Fudayl narrated to us, from al-‘Ala’, who said: I asked Sa‘id ibn Jubayr, and I said: "I perform ablution, then I take the bucket and draw water with it, and the rope scratches me, or the scratch afflicts me, and blood comes out of it." He said: "Wash it, and do not perform ablution."