What is the authenticity of the story of the man who recited Surat Taha and then saw in a dream a scroll containing the good deeds of his recitation, except for one word whose good deeds were erased because he raised his voice with it so that a man might pass by?

Hypocrisy (riyaa') and seeking a reputation (sum'ah) prevent the acceptance of good deeds, as indicated by the hadith: "He who lets others hear of his good deeds, Allah will let others hear of him; and he who makes a display of his good deeds, Allah will make a display of him."