Al-Kāfi
Hadith 13972ـ مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ هِشَامِ بْنِ سَالِمٍ عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ عَنْ أَبِي جَعْفَرٍ (عَلَيْهِ الْسَّلام) قَالَ إِنَّ الْعَبْدَ لَيُرْفَعُ لَهُ مِنْ صَلاَتِهِ نِصْفُهَا أَوْ ثُلُثُهَا أَوْ رُبُعُهَا أَوْ خُمُسُهَا فَمَا يُرْفَعُ لَهُ إِلاَّ مَا أَقْبَلَ عَلَيْهِ بِقَلْبِهِ وَإِنَّمَا أَمَرْنَا بِالنَّافِلَةِ لِيَتِمَّ لَهُمْ بِهَا مَا نَقَصُوا مِنَ الْفَرِيضَةِ.
2. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Ibn Abi ‘Umayr Hisham ibn Salim from Muhammad ibn Muslim who has said the following: “Abu Ja‘far (a.s.), has said, ‘Of Salah (prayer) of a servant (of Allah) sometimes one-half, sometimes one-third, one-fourth or one-fifth is raised. Whatever is raised is only what one has performed with love from his heart. We only command to perform optional Salah (prayer) to complete what it is cut short of obligatory ones.’”