رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 1760
The Book of the Prohibited actions
Abomination of Selecting Friday for Fasting
عَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّه عَنْهُ عَنِ النَّبِيِّ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ قَالَ: لاَ تخصوا لَيْلَةَ الْجُمُعَةِ بِقِيَامٍ مِنْ بَيْنِ اللَّيَالِي، وَلاَ تَخُصُّوا يَوْمَ الْجُمُعَةِ بِصِيَامٍ مِنْ بَيْنِ الأَيَّامِ إِلاَّ أَنْ يَكُونَ فِي صَوْمٍ يَصُومُهُ أَحَدُكُمْ ((رَوَاهُ مُسْلِم)).
Abu Hurairah (May Allah be pleased with him) reported: The Prophet (ﷺ) said, "Do not choose the Friday night among all other nights for standing in (Tahajjud) prayer, and do not choose Friday among all other days for Saum (fasting) except that one you have accustomed to." [Muslim].
Riyad as-Salihin, 1760