Al-Kāfi
Hadith 7214ـ الْحُسَيْنُ بْنُ مُحَمَّدٍ عَنْ مُعَلَّى بْنِ مُحَمَّدٍ عَنِ الْحَسَنِ بْنِ عَلِيٍّ الْوَشَّاءِ عَنِ الرِّضَا (عَلَيهِ السَّلام) قَالَ مَنْ فَرَّجَ عَنْ مُؤْمِنٍ فَرَّجَ الله عَنْ قَلْبِهِ يَوْمَ الْقِيَامَةِ.
4. Al-Husayn ibn Muhammad has narrated from Mu’alla ibn Muhammad from al- Hassan ibn Ali al-Washsha’ from al-Rida (a.s.) who has said the following: “Whoever relieves a believer from suffering, Allah will provide relief for his (helper’s) heart on the Day of Judgment.”