The Qurʾan Clarifies that the Sunnah is a Revelation from Allah

The two revelations (i.e., the Qur'an and the Sunnah) have been mentioned together in the Qur'an in a number of Ayat, like the saying of Allah, Exalted be He, addressing His Prophet ﷺ, {And We have also sent down unto you (O Muhammad ﷺ) the Dhikr (i.e., the Qur'an) that you may explain clearly to men what is sent down to them.} [Surah An-Nahl, 44] In this Ayah, there's a clear nass (textual evidence) that the explanation of the Prophet ﷺ is something that's additional to the Qur'an, and that the Qur'an is explained by his ﷺ explanation. So, what is explained is one thing and the explainer is something else which is additional to it, even though it is from a single niche (i.e., both revelations are from Allah).