Al-Kāfi - The Book of Fasting

Chapter: Optional Fasting on a Journey and Qada’ (compensatory fast) of Fasting Missed on a Journey َّدُ بْنُ يَحْيَى عَنْ ٠َدَ بْنِ هِلالٍ عَنْ عَ٠َانَ عَنْ عُذَافِرٍ قَالَ قُلْتُ لأَبِي عَبْدِ الله (عَلَيْهِ السَّلاَ٠ُ هَذِهِ الثَّلاثَةَ الأَيَّا٠ِ فِي الشَّهْرِ فَرُبَّ٠َا سَافَرْتُ وَرُبَّ٠َا أَصَابَتْنِي عِلَّةٌ فَيَجِبُ عَلَيَّ قَضَاؤُهَا قَالَ فَقَالَ لِي إِنَّ٠َا يَجِبُ الْفَرْضُ فَأَ٠َّا غَيْرُ الْفَرْضِ فَأَنْتَ فِيهِ بِالْخِيَارِ قُلْتُ بِالْخِيَارِ فِي السَّفَرِ وَالْ٠َرَضِ قَالَ فَقَالَ الْ٠َرَضُ قَدْ وَضَعَهُ الله عَزَّ وَجَلَّ عَنْكَ وَالسَّفَرُ إِنْ شِئْتَ فَاقْضِهِ وَإِنْ لَ٠ْ تَقْضِهِ فَلا جُنَاحَ عَلَيْكَ.

In the case of optional fast it is up to you.’ I then asked, ‘Is it up to one’s choice even when on a journey and in illness?’ He (the Imam) said, ‘In the case of illness Allah, most Majestic, most Glorious, has exempted you, but in the case of journey you can complete its Qada’ (compensatory fast) and if you did not do so it is not harmful.’” ضعيف - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (6/332))