Hadith 990
وَقَالَ: «إِنَّمَا الصَّلَاةُ لِقِرَاءَةِ الْقُرْآنِ وَذِكْرِ اللَّهِ فَإِذا كنت فِيهَا ليكن ذَلِك شَأْنك» . رَوَاهُ أَبُو دَاوُد
He then returned my greeting and said, “Prayer is solely for the purpose of reciting the Qur’an and making mention of God, so when you are engaged in it let that be what occupies your attention.” Abu Dawud transmitted it.