حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنْ سَعِيدِ بْنِ أَبِي عَرُوبَةَ، عَنْ قَتَادَةَ، أَنَّ أَنَسَ بْنَ مَالِكٍ، حَدَّثَهُمْ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏مَا بَالُ أَقْوَامٍ يَرْفَعُونَ أَبْصَارَهُمْ فِي صَلاَتِهِمْ ‏"‏ ‏.‏ فَاشْتَدَّ قَوْلُهُ فِي ذَلِكَ فَقَالَ ‏"‏ لَيَنْتَهُنَّ عَنْ ذَلِكَ أَوْ لَتُخْطَفَنَّ أَبْصَارُهُمْ ‏"

Anas b. Malik reported the Messenger of Allah (ﷺ) assaying

What is the matter with people who raise their eyes towards the sky during their prayer? He spoke very sternly about that, and said: 'They must stop doing that, or else their sight will be snatched away.'