If someone has been affected by sihr (witchcraft) and cannot fast, should he feed poor people instead?
Question

There is a thirty-three year old woman who has been affected by sihr (witchcraft) for approximately five years. She does not pray or fast, no matter how hard we try with her, and she cannot bear to hear the Qur’an even for a few moments. Sometimes she is not completely in her right mind. My question is: does she have to offer expiation for not fasting, by feeding poor people, when Ramadan comes?
Praise be to Allah.The impact of sihr may vary and there are different scenarios.
The first scenario:
This is when the sihr affects the mind, so that the person affected is not in control of his own affairs; he says words that he does not want to say and does things that he does not want to do, and he neglects his duties without realising. In this case, he is not accountable and there is no sin on him for not praying and fasting, because he comes under the ruling on one who is mad or insane (majnun). The Prophet (blessings and peace of Allah be upon him) said: “The Pen has been lifted from three: from the one who is asleep until he wakes up, from the minor until he reaches puberty, and from the insane person until he comes to his senses.” Narrated by Abu Dawud in as-Sunan (no. 4403); classed as sahih by al-Albani in Sahih Abi Dawud.
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said: The scholars are unanimously agreed that the insane person and the minor who has not yet reached the age of discernment are not obliged to do physical acts of worship such as prayer, fasting and Hajj. End quote from Minhaj as-Sunnah (6/49).
Shaykh Ibn ‘Uthaymin (may Allah have mercy on him) said: Question: is one who has been affected by sihr like one who is mad or insane (majnun)? Yes – we ask Allah to keep us safe and sound – one who has been affected by sihr comes under the same heading as one who is mad or insane, so if he issues a divorce (talaq) it does not count as such, and if he swears an oath (eela’) not to have intercourse with his wife four four months, that eela’ is not valid, and if he divorces his wife by zihar (saying to her, “You are to me as my mother’s back”), his zihar is not valid, because the one who is affected by sihr is completely out of his mind."(Ash-Sharh al-Mumti‘  13/221).
The second scenario:
is when the person is in his right mind, but he is prevented from fasting because of sihr. In this case he must put effort into making himself do obligatory deeds, and he should recite a lot of dhikr and ruqyah.
It says in Fatawa al-Lajnah ad-Da’imah (1/283): Jinn possession of humans is something that is real. If the jinni tells the one whom he has possessed to do something haram, the afflicted one must adhere to the laws of Allah and disobey the jinni when he orders him to disobey Allah. If the jinni harms him, he must seek refuge with Allah from his evil and protect himself by reciting Qur’an and supplications seeking refuge with Allah as prescribed in Islamic teachings, and by reciting words of dhikr that are soundly narrated from the Prophet (blessings and peace of Allah be upon him). These include reciting Surat al-Fatihah, Surat al-Ikhlas (Qul Huwa Allahu Ahad) and Surat al-Falaq and Surat an-Nas (al-Mi‘wadhatayn). Then he should blow into his hands and wipe his face and whatever he can reach of his body with them. Then he should recite these three surahs again, blow into his hands and wipe his face and whatever he can reach of his body with them. Then he should recite them a third time, and blow into his hands, and wipe whatever he can reach of his body with them. And he may do ruqyah in other ways too, reciting other surahs and verses of the Qur’an, and reciting words of dhikr that are soundly narrated from the Prophet (blessings and peace of Allah be upon him), whilst turning to Allah and asking Him for healing and for protection against the devils among the jinn and humankind.
Please see the books al-Kalim at-Tayyib by Ibn Taymiyah, al-Wabil as-Sayyib by Ibn al-Qayyim and al-Adhkar by an-Nawawi for more details on different types of ruqyah.
‘Abdullah ibn Qa‘ud, ‘Abdullah ibn Ghadyan, ‘Abd ar-Razzaq ‘Afifi, ‘Abd al-‘Aziz ibn Baz. End quote.
If the woman is of this type, and the sihr has overwhelmed her to the extent that she is not able to fast, without any negligence on her part – even if she has the power of reasoning and is healthy both physically and mentally – then there is no sin on her, but she must make up the missed fasts when she recovers. That is because sihr is something from which there is hope of recovery, and if there is hope of recovery, all the patient has to do is make up the missed fasts, because Allah, may He be exalted, says (interpretation of the meaning):
{O you who have believed, decreed upon you is fasting as it was decreed upon those before you that you may become righteous
 [Fasting for] a limited number of days. So whoever among you is ill or on a journey [during them] - then an equal number of days [are to be made up]} [al-Baqarah 2:183-184].
If the sihr has had an impact on the body to the extent that she is not able to fast because of it:
if there is the hope that she will recover, then she has to make up the missed fasts. If there is no hope of recovery from what has happened to her body, and it makes it too difficult to fast, then in that case she may feed poor people instead, and she does not have to make up the missed fasts.
Please see also the answer to question no. 49944 .
The third scenario
is when the affected person is in his right mind sometimes and loses his mind sometimes. In this case, he is accountable during the times when he is in his right mind.
Shaykh Ibn ‘Uthaymin (may Allah have mercy on him) was asked: What is the ruling on fasting for one who is in his right mind sometimes and loses his mind at other times? Or if he is incoherent one day and coherent the next day?
He replied: The ruling is connected to the reason for it. At times when he is coherent and in his right mind, he must fast, and at times when he is out of his mind and incoherent, he is not obliged to fast.
If we assume that he is out of his mind on one day and is in his right mind on another day, or he is incoherent on one day and coherent on another day, then on the day on which he is coherent, he is obliged to fast, and on the day on which he is not coherent, he is not obliged to fast."(Fatawa Ibn ‘Uthaymin 19/88).
And Allah knows best.