It was narrated from Abu Hurairah that the Messenger of Allah ﷺ said:
“There are people who fast and get nothing from their fast except hunger, and there are those who pray and get nothing from their prayer but a sleepless night.”

حَدَّثَنَا عَمْرُو بْنُ رَافِعٍ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ الْمُبَارَكِ، عَنْ أُسَامَةَ بْنِ زَيْدٍ، عَنْ سَعِيدٍ الْمَقْبُرِيِّ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ ـ ﷺ ـ " رُبَّ صَائِمٍ لَيْسَ لَهُ مِنْ صِيَامِهِ إِلاَّ الْجُوعُ وَرُبَّ قَائِمٍ لَيْسَ لَهُ مِنْ قِيَامِهِ إِلاَّ السَّهَرُ " .