مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 2070
Fasting
Voluntary Fasting - Section 3
وَعَنْ حَفْصَةَ قَالَتْ: أَرْبَعٌ لَمْ يَكُنْ يَدَعُهُنَّ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «صِيَامُ عَاشُورَاءَ وَالْعَشْرِ وَثَلَاثَةُ أَيَّامٍ مِنْ كُلِّ شَهْرٍ وَرَكْعَتَانِ قبل الْفجْر» . رَوَاهُ النَّسَائِيّ
Hafsa said there were four things the Prophet (ﷺ) never omitted: fasting on ‘Ashura’, the first ten days of Dhul Hijja* and three days every month, and praying two rak'as before dawn. *The Arabic has simply 'the ten', to be understood as translated above. Nasa’i transmitted it.
Mishkat al-Masabih, 2070لم تتمّ دراسته (الألباني)