The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 1726
Ibn Mas'ud reported Allah's Messenger (may peace be upon him) as saying: Wretched is the man who says: I forgot such and such a sura, or I forget such and such a verse, but he has been made to forget.
Source materials are from the University of Southern California MSA site|
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