minutes—this entire interval is a valid time for the two rakʿahs of the Duha prayer.
It is recommended to perform them every day, for the Prophet ﷺ said: “Every joint of the children of Adam incurs a charity each day, and there are three hundred and sixty joints. Thus three hundred and sixty acts of charity are due each day. Those charities are not confined to money: every utterance of ‘Subḥān Allah’ is a charity, every ‘Allāhu akbar’ is a charity, every ‘Lā ilāha illā Allāh’ is a charity. Enjoining what is right is a charity, forbidding what is wrong is a charity—even helping a man mount his riding animal is a charity, and a man’s intimacy with his wife is a charity.”
Yet the Prophet ﷺ also said, “Two rakʿahs offered at Duha suffice for all of that.”
Hence, when you pray two rakʿahs of Duha you have discharged the charities that are due from you each day, and whatever remains is counted as voluntary.
As for the third counsel—“and that I perform Witr before I sleep”—this applies to the one who fears he may not rise toward the end of the night. Such a person should pray Witr before going to bed, as a safeguard. Whoever hopes to rise for worship in the last part of the night should delay his Witr until then, for that is how it has come in the Sunnah of the Prophet ﷺ.
The scholars explain that the Prophet recommended these Companions to pray Witr before sleeping because their circumstances warranted it. Abu Hurayrah, for instance, would stay awake during the early part of the night preserving the hadiths of the Messenger of Allah and then sleep toward its end.
Moreover, with regard to the three days, you may fast them in the first ten days, or in the ten—