Is regularly reciting Surat Al-A'la and Al-Kafirun in the Witr prayer from the Sunnah, and is regularly reciting Al-Kafirun and Al-Ikhlas in the Sunnah prayer of Fajr legitimate, or did the Prophet, may Allah bless him and grant him peace, not do so regularly?

The Prophet, peace and blessings be upon him, used to recite "Glorify the Name of your Most High Lord" (Surat Al-A'la) in the first unit (rak'ah) of the Witr prayer, "Say, 'O disbelievers!'" (Surat Al-Kafirun) in the second, and "Say, 'He is Allah, [who is] One'" (Surat Al-Ikhlas) in the third. However, one should not always persist in this practice lest it be believed to be obligatory, as the Prophet, peace and blessings be upon him, also recited other surahs in Witr.

As for the two units of Fajr (dawn) prayer, various recitations have been reported. The Prophet, peace and blessings be upon him, sometimes recited "Al-Kafirun" and "Al-Ikhlas" in them. At other times, he would recite in the first unit, "Say, 'We believe in Allah and what was revealed to us'" (Surat Al-Baqarah, part of verse 136), and in the second, "Say, 'O People of the Scripture, come'" (Surat Aal 'Imran, part of verse 64), or "And when Jesus perceived [their] disbelief" (Surat Aal 'Imran, part of verse 52). It is preferable for a Muslim to do this at one time and that at another time. And if one recites other than these, it is still sufficient.