Muwatta Malik 224
موطأ مالك#224Da'ifThese are the words of a Successor — the generation after the Companions — not of the Prophet ﷺ.
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ رَجُلاً، سَأَلَ الْقَاسِمَ بْنَ مُحَمَّدٍ فَقَالَ إِنِّي أَهِمُ فِي صَلاَتِي فَيَكْثُرُ ذَلِكَ عَلَىَّ . فَقَالَ الْقَاسِمُ بْنُ مُحَمَّدٍ امْضِ فِي صَلاَتِكَ فَإِنَّهُ لَنْ يَذْهَبَ عَنْكَ حَتَّى تَنْصَرِفَ وَأَنْتَ تَقُولُ مَا أَتْمَمْتُ صَلاَتِي .
Yahya related to me from Malik that he had heard that a man questioned al-Qasim ibn Muhammad saying, "My imagination works in the prayer, and it happens to me a lot." Al-Qasim ibn Muhammad said, "Go on with your prayer, for it will not go away from you until you go away saying, 'I have not completed my prayer
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 4:3