Sahih Muslim 2684
صحيح مسلم#2684SahihAbu Huraira (Allah be pleased with him) reported Allah's Apostle (ﷺ) as saying: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)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 13:190