Al-Kāfi - The Book of Fasting

Chapter: The Limit of Illness That Exempts One from Fasting 3ـ عَلِيُّ بْنُ إِبْرَاهِي٠َّدِ بْنِ عِيسَى بْنِ عُبَيْدٍ عَنْ يُونُسَ عَنْ سَ٠َاعَةَ قَالَ سَأَلْتُهُ ٠َرَضِ الَّذِي يَجِبُ عَلَى صَاحِبِهِ فِيهِ الإِفْطَارُ كَ٠َا يَجِبُ عَلَيْهِ فِي السَّفَرِ ٠َرِيضاً أَوْ عَلَى سَفَرٍ قَالَ هُوَ ٠ُفَوَّضٌ إِلَيْهِ فَإِنْ وَجَدَ ضَعْفاً فَلْيُفْطِرْ وَإِنْ وَجَدَ قُوَّةً فَلْيَصُ٠3.

Ali ibn Ibrahim has narrated from Muhammad ibn ‘Isa ibn ‘Ubayd from Yunus from Sama‘ah, who has said the following: “I once asked him (the Imam) (a.s.), about the limits of illness because of which it is obligatory on the patient not to fast as is the case on a journey, ‘... one who is on a journey or suffers from an illness....’ He (the Imam) said, ‘It is up to him to decide.

If he finds weakness, he eats and if he finds strength he fasts, regardless of the degree of illness.’” وثق - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (6/307))