Rafa Yadein
But this additional ibaadah is not in a vacuum. It is making a claim. It is saying ‘you can also do this in the salah- the shariah permits it’. This is a claim that is supported by none other than the ahadeeth. So it technically IS adding into the religion. The point is we can use ahadeeth for uswa etc but for something that is transmitted solely by ijma and tawattur like salah or the method of it why are we looking somewhere else? For the nafil prayers I would think that that is also transmitted with ijma and tawattur. No one says it’s haraam to pray nafil or fard. They all say it’s optional (some confused people use different terms but don’t say fard at least). Rafa yadein, however, is not transmitted with this ijma and tawattur so shouldn’t be included in the shariah of salah It is not introducing a completely new ibaadah (as you have said) but it is still adding to the directive of the prayer (the shariah of it I mean).
Does ijma have to include every sect? Because ibadi sect doesn’t do rafa yadain at all