Al-Kāfi

Hadith 182
taqwaasceticism
4ـ عِدَّةٌ مِنْ أَصْحَابِنَا عَنْ أَحْمَدَ بْنِ مُحَمَّدِ بْنِ خَالِدٍ عَنِ ابْنِ فَضَّالٍ عَنْ أَبِي جَمِيلَةَ عَنِ ابْنِ أَبِي يَعْفُورٍ عَنْ أَبِي عَبْدِ الله (عَلَيهِ السَّلام) قَالَ لا يَنْفَعُ اجْتِهَادٌ لا وَرَعَ فِيهِ.
4. A number of our people have narrated from Ahmad ibn Muhammad ibn Khalid from ibn Faddal from abu Jamilah from ibn abu Ya’fur from Abu ‘Abdillah (a.s.) who has said the following: “Abu ‘Abd Allah (a.s.) has said, ‘Hard work without restraint from worldly things (sins) is of no benefit.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī