In a statement put on islamonline.net it stated with regards to a famous hadeeth about Musical instruments. "Although this hadith is in Sahih Al-Bukhari, its chain of transmission is not connected to Prophet Muhammad (peace and blessings be upon him) and this invalidates its authenticity. Ibn Hazm rejects it for that very reason. Moreover, the sub-narrator, Hisham Ibn `Ammar is declared ‘weak’ by many scholars of the Science of Hadith Methodology."

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So I don't get it, is a weak hadeeth still applied to the Prophet?