I say: The hadith indicates that it is recommended to persist in offering twelve voluntary rak‘ahs every day.

Whoever consistently observes the regular sunnah prayers attains the virtue mentioned in this hadith, since he assuredly offers twelve or more rak‘ahs each day.

Thus, the hadith establishes the virtue of consistently observing the regular sunnah prayers in general, and those mentioned in the hadith in particular. And Allah knows best.

The Messenger’s own observance of the regular sunnah prayers is also authentically established—peace and blessings be upon him. Thus, both his words and his practice attest to them.

b) Ibn ‘Umar—may Allah be pleased with them both—said: “I memorized from the Prophet—peace and blessings be upon him—ten rak‘ahs: two before Zuhr, two after it, two after Maghrib in his home, two after Ishā in his home, and two before Fajr prayer. This was a time when no one would enter upon the Prophet—peace and blessings be upon him. Hafsah told me that when the muezzin called the adhān and dawn broke, he would offer two rak‘ahs.”

A similar narration by al-Bukhārī and Muslim adds: “And two rak‘ahs after the Friday prayer.”