Al-Kāfi - Volume 4 > The Excellence of Fast and Fasting
Hadith #6

6ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ سَلَمَةَ صَاحِبِ السَّابِرِيِّ عَنْ أَبِي الصَّبَّاحِ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ السَّلاَم) قَالَ إِنَّ الله تَبَارَكَ وَتَعَالَى يَقُولُ الصَّوْمُ لِي وَأَنَا أَجْزِي عَلَيْهِ.

6. Ali ibn Ibrahim has narrated from his father from ibn abu ‘Umayr from Salamah, Sahib al-Sabiriy from abu al-Sabbah who has said the following: “Abu ‘Abd Allah, ‘Alayhi al-Salam, has said that Allah, the most Blessed, the most High, has said, ‘Fasting is for Me, and I reward for it.’”