Sunan Ibn Majah, Book 5, Hadith 963 (In-Book) ⓘ
It was narrated that Abu Hurairah said: “The Messenger of Allah said to a man: ‘What do you say during your Salat?’ He said: ‘The Tashah-hud, then I ask Allah for Paradise, and I seek refuge with Him from Hell, but I do not understand what you and Mu’adh murmur (during Salat). He said: ‘Our murmuring revolves around the same things.’”
حَدَّثَنَا يُوسُفُ بْنُ مُوسَى الْقَطَّانُ، حَدَّثَنَا جَرِيرٌ، عَنِ الأَعْمَشِ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ لِرَجُلٍ " مَا تَقُولُ فِي الصَّلاَةِ " . قَالَ أَتَشَهَّدُ ثُمَّ أَسْأَلُ اللَّهَ الْجَنَّةَ وَأَعُوذُ بِهِ مِنَ النَّارِ أَمَا وَاللَّهِ مَا أُحْسِنُ دَنْدَنَتَكَ وَلاَ دَنْدَنَةَ مُعَاذٍ . فَقَالَ " حَوْلَهُمَا نُدَنْدِنُ " .
also referenced under: Hadith 910 (Reference) & Volume 2, Book 5, Hadith 910 (DarusSalam)