Sahih Muslim
Sahih Muslim 1143 a
It is disliked to single out Friday for fasting, unless it coincides with a day that one customarily fasts
Arabic hadith text
حَدَّثَنَا عَمْرٌو النَّاقِدُ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنْ عَبْدِ الْحَمِيدِ بْنِ جُبَيْرٍ، عَنْ مُحَمَّدِ، بْنِ عَبَّادِ بْنِ جَعْفَرٍ سَأَلْتُ جَابِرَ بْنَ عَبْدِ اللَّهِ - رضى الله عنهما - وَهُوَ يَطُوفُ بِالْبَيْتِأَنَهَى رَسُولُ اللَّهِ صلى الله عليه وسلم عَنْ صِيَامِ يَوْمِ الْجُمُعَةِ فَقَالَ نَعَمْ وَرَبِّ هَذَا الْبَيْتِ .
Translation
Muhammad b. 'Abbas b. Ja'far reported
I asked Jabir b. 'Abdullah (Allah be pleased with both of them) as he was circumambulating the House (Ka'ba) whether the Messenger of Allah (ﷺ) had forbidden the fasting on Friday, whereupon he said: Yes, by the Lord of this House.