"The Messenger of Allah used to fast three days in the middle of every month, and he rarely did not fast on Friday." (Using translation from Nasāʾī 2368)
كَانَ رَسُولُ اللهِ ﷺ يَصُومُ ثَلَاثَةَ أَيَّامٍ مِنْ غُرَّةِ كُلِّ هِلَالٍ وَقَلَّمَا كَانَ يُفْطِرُ يَوْمَ الْجُمُعَةِ