The prohibition of lifting one's gaze to the sky when supplicating during the prayer
أَخْبَرَنَا أَحْمَدُ بْنُ عَمْرِو بْنِ السَّرْحِ، عَنِ ابْنِ وَهْبٍ، قَالَ أَخْبَرَنِي اللَّيْثُ، عَنْ جَعْفَرِ بْنِ رَبِيعَةَ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " لَيَنْتَهِيَنَّ أَقْوَامٌ عَنْ رَفْعِ أَبْصَارِهِمْ عِنْدَ الدُّعَاءِ فِي الصَّلاَةِ إِلَى السَّمَاءِ أَوْ لَتُخْطَفَنَّ أَبْصَارُهُمْ " .
It was narrated from Abu Hurairah that: The Messenger of Allah (ﷺ) said: "People should certainly stop lifting their gaze to the sky when they supplicate during the prayer, or they will lose their eyesight."