مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 2108
Fasting
Private Devotional Exercises in a Mosque - Section 3
وَعَنِ ابْنِ عَبَّاسٍ: أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ فِي الْمُعْتَكَفِ: «هُوَ يَعْتَكِفُ الذُّنُوبَ وَيُجْرَى لَهُ مِنَ الْحَسَنَاتِ كَعَامِلِ الْحَسَنَات كلهَا» . رَوَاهُ ابْن مَاجَه
Ibn ‘Abbas reported God’s messenger as saying about one who observes a period of private devotion in a mosque, “He turns away from sins and he is rewarded for good deeds like one who does all good deeds.” Ibn Majah transmitted it.
Mishkat al-Masabih, 2108