AbuSalih reported on the authority of some Companions of the Prophet ﷺ: The Prophet ﷺ said to a person: what do you say in prayer? He replied: I first recite tashahhud (supplication recited in sitting position), and then I say: O Allah, I ask Thee for Paradise, and I seek refuge in Thee from Hell-Fire, but I do not understand your sound and the sound of Mu'adh (what you say or he says in prayer). The Prophet ﷺ said: We too go around it (paradise and Hell-fire). (Using translation from Abū Dāʾūd 792)  

عَنْ بَعْضِ أَصْحَابِ النَّبِيِّ ﷺ قَالَ قَالَ النَّبِيُّ ﷺ لِرَجُلٍ كَيْفَ تَقُولُ فِي الصَّلَاةِ؟ قَالَ أَتَشَهَّدُ ثُمَّ أَقُولُ اللهُمَّ إِنِّي أَسْأَلُكَ الْجَنَّةَ وَأَعُوذُ بِكَ مِنَ النَّارِ أَمَا إِنِّي لَا أُحْسِنُ دَنْدَنَتَكَ وَلَا دَنْدَنَةَ مُعَاذٍ فَقَالَ النَّبِيُّ ﷺ حَوْلَهَا نُدَنْدِنُ