“How many a fasting person is there who has nothing from his fast except hunger! And how many a standing-in-prayer person is there who has nothing from his night prayer except sleeplessness!”
Narrated by Aḥmad (no. 9685), and the wording is his; al-Nasāʾī in al-Sunan al-Kubrā (no. 3236); and Ibn Mājah (no. 1690), with the wording: “Rubb (perhaps) a fasting person has nothing from his fast except hunger…”, from the narration of Abū Hurayrah (may Allah be pleased with him).
Authenticated in Ṣaḥīḥ al-Jāmiʿ (no. 3488) and Ṣaḥīḥ al-Targhīb wa al-Tarhīb (no. 1083).
Brief Explanation of the Hadith
Fasting, night prayer, and all righteous deeds are not accepted by Allah the Exalted except with sincerity to Him and with avoidance of that which nullifies or diminishes their reward.
The meaning of this ḥadīth is to clarify the condition of many people who fast, yet gain nothing from their fasting except hunger and thirst. Either because of a corrupted intention—thus they are deprived of the reward of obedience due to the absence of the condition of acceptance, which is sincerity—as in the ḥadīth of Abū Hurayrah (may Allah be pleased with him) reported by Muslim: “I am the One Who is most free of any need of partners. Whoever performs a deed in which he associates someone else with Me, I abandon him and his shirk.”
It may also be intended as a form of emphatic warning, with the negation here understood as a negation of completeness—that is, their reward is diminished due to committing what reduces it, such as lying, backbiting, slander, and other major sins. The same applies to standing in night prayer: a person may prolong his worship through prayer, recitation of the Qurʾān, and remembrance, yet still be deprived of the reward of his obedience because of a corrupted intention.
The ḥadīth thus indicates the obligation of sincerity in one’s deeds for Allah, the Exalted, and warns against that which nullifies or diminishes them. And in the Prophet’s words, “How many…” there is an indication of their great number—so the Muslim must beware lest he be among them.