"The Messenger of Allah commanded me to pray two Rakahs of Duha, and not to sleep until I had prayed witr, and to fast three days each month." (Using translation from Nasāʾī 2369)
أَنْ لَا أَنَامَ إِلَّا عَلَى وِتْرٍ وَصَوْمِ ثَلَاثَةِ أَيَّامٍ مِنْ كُلِّ شَهْرٍ وَرَكْعَتَيِ الضُّحَى