Sunnah With Tawatur
This has been discussed in detail in the program series Ijma and Tawatur. Tawatur is initially and essentially found in the actions of the ummah. The books of fiqh just record them. The whole ummah agrees upon certain actions to be religious rituals transmitted to them from the former generations. It is not possible that the whole ummah agreed upon them when there were some differences in the past. All the books of Fiqh find their reference in the previous books. There is no difference in the content of Sunnah among the books of fiqh. They are the same in recording Sunnah. No bidah can be universally accepted by the whole ummah as sunnah.