Hadith 2070

Hafsa said there were four things the Prophet 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.

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

Reference: 5620700
In-book reference: Book 7, Hadith 2070