Sunnat Ka Makhaz
The remnants of the tradition of Ibrahim in the Arab society and what was being practiced by Jews, the teaching of Jibrael (for example, He taught prayers and their timing to the prophet), and the guidance of Wahi helped revive the sunnah with some amendments. The proof of wahi in this case is the Quran; it discusses Sunnah when necessary. For example, wudu, fast, mehram women, etc.