✨Ruling for One Who Eats or Drinks by Mistake during fasting
Abu Hurayrah (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Whoever forgets he is fasting and eats or drinks, let him complete his fast for it is Allaah Who has fed him and given him to drink.”
This hadeeth indicates that whoever eats or drinks by mistake, his fast is still valid and is not affected, nor is there any sin on him, because he did not do that deliberately, rather is it a provision that Allaah granted to him.
Hence his being fed and given to drink is attributed to Allaah.
And whatever is attributed to Allaah, a person cannot be taken to task for that, because he was only forbidden to do it, but he is not accountable for actions that are beyond his control. No distinction is made between eating and drinking, or whether it is a little or a lot, because of the general meaning of the hadeeth.
He does not have to make up that day because he is commanded to complete the fast and that which is completed is regarded as a fast.
The fact that the fast of one who eats or drinks by mistake is still valid and that he does not have to make it up is something on which there is (scholarly) consensus, although Imam Maalik and Ibn Abi Layla disagreed.
An analogy is drawn between eating and drinking and other things that invalidate the fast, because of the hadeeth of Abu Salamah ibn ‘Abd al-Rahmaan, narrating from Abu Hurayrah (may Allaah be pleased with him), who said that the Prophet (peace and blessings of Allaah be upon him) said: “Whoever breaks the fast in Ramadaan by mistake does not have to make up that day or offer any expiation.”
<∆>This ruling concerning the fasting person is one of the great principles mentioned in the verse (interpretation of the meaning):
“Our Lord! Punish us not if we forget or fall into error” [al-Baqarah 2:286]
According to a saheeh hadeeth, Allaah says, in answer to this du’aa’: “I have done that”; according to another report: “Yes.”
This is by the kindness of Allaah towards His slaves, to make it easier for them and to relieve them of hardship and difficulty.
The Prophet (peace and blessings of Allaah be upon him) said: “Allaah has forgiven my ummah for mistakes, forgetfulness and what they are forced to do.”
What if I see a fasting person eating or drinking by mistake – do I have to remind him?
Whoever sees a fasting person eating or drinking during the day in Ramadaan by mistake is obliged to tell him and remind him, because this comes under the heading of enjoining what is good and forbidding what is evil.
Eating and drinking during the day in Ramadaan is a wrong action but the one who does it by mistake because he forgot is excused, but he must be told immediately.
If a person does ghusl or rinses his mouth or nose and water enters his throat by accident, that does not invalidate his fast. The same applies if a fly or gnat flies into one’s mouth, or if gasoline reaches his throat without him intending it to; that does not invalidate his fast, because it is not possible to avoid that, and because he did not intend that or want it to happen. This is like the person who forgets and does not do such things deliberately or by choice. Hence al-Bukhaari (may Allaah have mercy on him) said in his Saheeh: “Chapter on a fasting person if he eats or drinks because he forgets.”
Then he said:
‘Ata’ said: If a person rinses his nose and water enters his throat, then is no sin on him because he did not intend to do that. But if he can prevent the water from entering his throat, but he does not try to stop it and instead swallows it, then he breaks his fast.
And Allaah knows best.
Source:
https://islamqa.info - Islam Question and Answer
Ahkaam al-Siyaam by al-Fawzaan, p. 39.