It wasnarrated from Abu Hurairah that the Messenger of Allah (ﷺ)said:
"There are people who fast and get nothing from their fastexcepthunger, and there are those who pray and get nothing from theirprayer but a sleepless night." (FR)
English reference (FR): Vol. 1, Book 7, Hadith 1690 (FR)
Arabic reference (FR): Book 7, Hadith 1760 (FR)