Hadithcore
Riyad as-Salihin, 1763

Juwairiyah bint Al-Harith (May Allah be pleased with her), the Mother of the Believers, said that the Prophet (ﷺ) visited her on a Friday and she was observing fast. He asked, "Did you observe fast yesterday?" She said, "No." He asked, "Do you intend to observe fast tomorrow?" She said, "No." He said, "In that case, give up your fast today." <b>[Al-Bukhari]</b>.

وعن أم المؤمنين جويرة بنت الحارس رضي الله عنها أن النبي صلى الله عليه وسلم دخل عليها يوم الجمعة وهي صائمة، فقال‏:‏ ‏"‏ أصمت أمس‏؟‏‏"‏ قالت‏:‏ لا، قال‏:‏ ‏"‏ تريدين أن تصومي غدا ‏"‏ قالت‏:‏ لا، قال ‏:‏ ‏"‏فأفطري‏"‏ ‏(‏‏(‏رواه البخاري‏)‏‏)‏

References1 variant
In-Book Reference
Book 17, Hadith 253
Sharh · explanationclick to expand
<b>Guidance from the Hadiths:</b><br> 1) It is prohibited to single out Friday alone for fasting. But it is permissible to fast it along with a day before or a day after.<br> 2) It is not permissible to single out the night of Friday for performing voluntary night prayer, as linking any act of worship to a particular time requires a Shariah proof.<br> Note:<br> He who performs the voluntary night prayer on a regular basis is not subject to this prohibition. It is permissible for him to perform it on Friday night, for he does not single it out for this worship, and Allah knows best.