What is the rationale for adding the section of tawhid al-mutaba'ah (following the Prophet) to the categories of tawhid, and does it have a basis?

Question:
I read a phrase in some contemporary books that focus on tawhid (the oneness of Allah) and explain it, which confused me. It states that tawhid is divided into four categories: tawhid al-uluhiyyah (oneness of worship), tawhid al-rububiyyah (oneness of lordship), tawhid al-asma' wa al-sifat (oneness of the names and attributes), and the fourth is tawhid al-mutaba'ah. The question is: what is the rationale for adding this fourth category to those categories? And does it have a basis?

Answer:
This is an innovation from his own mind. An innovation from his own mind. This falls under tawhid. Tawhid is regarding Allah (Mighty and Majestic). As for the right of the Messenger, it is following him. The one who errs in following is called an innovator. The one who errs in tawhid is called one who associates partners with Allah. There is a difference between them. The opposite of tawhid is shirk (associating partners with Allah). The opposite of following is bid'ah (religious innovation). There is a difference between them. Yes.