Sahih Muslim
Sahih Muslim 136 a
Clarifying the Waswasah (Whispers, Bad Thoughts) with regard to faith, and what the one who experiences that should say
Arabic hadith text
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ عَامِرِ بْنِ زُرَارَةَ الْحَضْرَمِيُّ، حَدَّثَنَا مُحَمَّدُ بْنُ فُضَيْلٍ، عَنْ مُخْتَارِ بْنِ فُلْفُلٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " قَالَ اللَّهُ عَزَّ وَجَلَّإِنَّ أُمَّتَكَ لاَ يَزَالُونَ يَقُولُونَ مَا كَذَا مَا كَذَا حَتَّى يَقُولُوا هَذَا اللَّهُ خَلَقَ الْخَلْقَ فَمَنْ خَلَقَ اللَّهَ " .
Translation
Anas b. Malik transmitted it from the Messenger of Allah (ﷺ) that the Great and Glorious Allah said
Verily your people would constantly question about this and that till they would say: Well, it is Allah Who created the creation, but who created Allah?