أَوْصَانِي بِصَلاَةِ الضُّحَى وَبِالْوِتْرِ قَبْلَ النَّوْمِ وَبِصِيَامِ ثَلاَثَةِ أَيَّامٍ مِنْ كُلِّ شَهْرٍ .
It was narrated that Abu Dharr said: "My beloved Prophet advised me to do three things which I will never give up, if Allah wills. He advised me to pray Duha, to pray Witr before sleeping, and to fast three days of each month."