Abu Hurayrah, may Allah be pleased with him, narrated that the Prophet, , said, “If a fasting person has a sudden attack of vomiting, he is not required to make up for that day; but, if he throws up intentionally, he must make up for it.” [Abu Daawood]
Ma‘daan ibn Talhah said, “Abu Ad-Dardaa’, may Allah be pleased with him, told me that the Prophet vomited and broke his fast. When I met Thawbaan, may Allah be pleased with him, in the mosque of Damascus I told him about what Abu Ad-Dardaa’ had said. He confirmed it, adding, ‘I was the one who poured the water for the Prophet to perform ablution.’”[Abu Daawood]
Benefits and rulings [derived from these Hadeeths]:
1- One of the manifestations of the Mercy of Allah The Almighty upon His slaves is that He does not punish them for whatever happens against their will. A person is only accountable for his deliberate actions, such as vomiting on purpose, which invalidates one’s fast. Premeditated vomiting occurs when one puts his finger or anything else in his throat, smells something foul, sees a disturbing image or employs any other method, with the intention to throw up. However, if it happens involuntarily, then it does not invalidate the fast, as per the unanimous agreement of the scholars and in accordance with the meaning of the aforementioned Hadeeths.
2 - The last Hadeeth, which states that the Prophet, , threw up and broke his fast means that vomiting weakened him, which is why he broke his fast, not [some wrong notion that] unintentional vomiting nullifies the fast. That is how the honorable scholars understood the two relevant Hadeeths. In addition, according to At-Tahaawi’s narration, the Prophet, , specifically said, “I vomited and this weakened me, so, I broke my fast.”
3- It is impermissible for the fasting person to vomit deliberately during the daytime in Ramadan, because this invalidates his fast, unless he is sick and requires it. In such a case, he is excused, as Allah The Almighty Says (what means): {So whoever among you is ill or on a journey [during them] - then an equal number of days [are to be made up]}[Quran 2:184], i.e., one is allowed to break his fast and then make up for it.
4 -The fact that the Sharee‘ah (Islamic jurisprudence) rendered deliberate vomiting as an act that annuls the fast, proves that it is just, for all Decrees of Allah The Almighty are fair and merciful. Shaykh Al-Islam Ibn Taymiyyah said, “The fasting person is forbidden from consuming what strengthens and nourishes him during the daytime. Conversely, he is not allowed to extract what may weaken him and decrease his nourishment; otherwise, the fasting person will harm himself and will thus be transgressing in his worship.”