What may not be done during Prayer and what is permitted - Section 1 Mishkat al-Masabih 983

Arabic hadith text
وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «لَيَنْتَهِيَنَّ أَقْوَامٌ عَنْ رَفْعِهِمْ أَبْصَارَهُمْ عِنْدَ الدُّعَاءِ فِي الصَّلَاةِ إِلَى السَّمَاءِ أَوْ لَتُخْطَفَنَّ أَبْصَارهم» . رَوَاهُ مُسلم
Translation

Abu Huraira reported God’s Messenger as saying, “People must stop raising their eyes to heaven while making supplication in prayer, otherwise their sight will be taken away.” Muslim transmitted it.