Other answers, that the words "Man Sanna" can also mean: "He turned a sunnah", which had been abandoned and never been there before. So the word "sanna" does not mean making the Sunnah of itself, but reviving a Sunnah that has been abandoned.
Kaya ang salitang "sanna" ay hindi nangangahulugan ng paggawa ng mga Sunnah ng kanyang sarili, ngunit reviving isang Sunnah na ay inabandunang.