Al-Kāfi

Hadith 172
prophet-muhammadasceticism
عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ هِشَامٍ وَ غَيْرِهِ عَنْ أَبِي عَبْدِ اللَّهِ (عليه السلام) قَالَ مَا كَانَ شَيْ‏ءٌ أَحَبَّ إِلَى رَسُولِ اللَّهِ (صلى الله عليه وآله) مِنْ أَنْ يُظِلَّ خَائِفاً جَائِعاً فِي اللَّهِ عَزَّ وَ جَلَّ.
171. Ali Bin Ibrahim, from his father, from Ibn Abi ‘Umayr, from Hisham and someone else, who has narrated the following: Abu Abdullah (asws) said: ‘There was nothing more beloved to the Rasool Allah (saww) than to remain fearful and hungry for the Sake of Allah (azwj) Mighty and Majestic’.
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī