The Prophet ﷺ said, "We are the last (to come) but we will be the foremost on the Day of Resurrection, nations were given the Book (i.e. Scripture) before us, and we were given the Holy Book after them. This (i.e. Friday) is the day about which they differed. So the next day (i.e. Saturday) was prescribed for the Jews and the day after it (i.e. Sunday) for the Christians. It is incumbent on every Muslim to wash his head and body on a Day (i.e. Friday) (at least) in every seven days." (Using translation from Bukhārī 3486)
عَنِ النَّبِيِّ ﷺ قَالَ نَحْنُ الْآخِرُونَ السَّابِقُونَ يَوْمَ الْقِيَامَةِ بِيَدِ كُلِّ أُمَّةٍ أُوتُوا الْكِتَابَ مِنْ قَبْلِنَا وَأُوتِينَا مِنْ بَعْدِهِمْ فَهَذَا الْيَوْمُ الَّذِي اخْتَلَفُوا فِيهِ فَهَدَانَا اللهُ فَغَدًا لِلْيَهُودِ وَبَعْدَ غَدٍ لِلنَّصَارَى فَسَكَتَ وَقَالَ حَقٌّ عَلَى كُلِّ مُسْلِمٍ فِي كُلِّ سَبْعَةِ أَيَّامٍ يَوْمًا يَغْسِلُ رَأْسَهُ وَجَسَدَهُ وَرَوَاهُ الْبُخَارِيُّ فِي الصَّحِيحِ عَنْ مُوسَى بْنِ إِسْمَاعِيلَ مُخْتَصَرًا