Al-Kāfi - Volume 4 > The Case of One Who Fasts on a Journey out of Ignorance
Hadith #2

2ـ أَبُو عَلِيٍّ الأَشْعَرِيُّ عَنْ مُحَمَّدِ بْنِ عَبْدِ الْجَبَّارِ عَنْ صَفْوَانَ بْنِ يَحْيَى عَنْ عِيصِ بْنِ الْقَاسِمِ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ السَّلاَم) قَالَ مَنْ صَامَ فِي السَّفَرِ بِجَهَالَةٍ لَمْ يَقْضِهِ.

2. Abu Ali al-Ash’ariy has narrated from Muhammad ibn ‘Abd al-Jabbar from Safwan ibn Yahya from ‘Is ibn al-Qasim who has said the following: “Abu ‘Abd Allah, ‘Alayhi al-Salam, has said, ‘One who fasts on a journey because of ignorance is not required to complete its Qada’ (compensatory fast)/”