This tradition has been transmitted by Hisham through a different chain of narrators to the same effect: Rub it off (with a stone), and then scratch it (with finger) by pouring water, then sprinkle water upon it.
Hadith Referenceسنن ابي داود / كتاب الطهارة / 362
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:إسناده صحيح
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