Do not single out the night (preceding) Friday among the nights for prayer and do not single out Friday among days for fasting but only when anyone among you is accustomed to fast (on dates) which coincide with this day (Friday). (Using translation from Muslim 1144b)
قَالَ رَسُولُ اللهِ ﷺ «لَا تَخْتَصُّوا لَيْلَةَ الْجُمُعَةِ بِقِيَامٍ مِنْ بَيْنِ اللَّيَالِي وَلَا تَخْتَصُّوا يَوْمَ الْجُمُعَةِ بِصِيَامٍ مِنْ بَيْنِ الْأَيَّامِ إِلَّا أَنْ يَكُونَ فِي صَوْمٍ يَصُومُهُ أَحَدُكُمْ»