Origins Of Beliefs :barelvis

[Chaotic Muslem]

Salamon Alaykum !

Peace be upon you all

I met some memebrs here who hold beliefs that I thought are mentioned in Shia books but the way they understand these beliefs was diffrent than my way particularly memebers from south Asia

One of the latest encounters is the nour/bashar (light/flesh) nature of our prophet and all the infallables which upon it they based their other belief that prophet had no shadow

These beliefs are held by the Barelvis as well, so I am not sure which was the root of this belief for some of the shia bretherns here

There were some topics about Barelvis discussing them in general, i find some of the posts there to be helpful but i am interested more about this specific belief of the nature of the prophet and its origin

According to wiki , the vast majority of muslims in India and Pakistan adhere to Barelvis along with about 35 % of mosques in UK.

Thats some huge number of Muslims that believe in things that shia believe in but in diffirent way .

Where did it all start? Is there some ancient agreement between scholars of muslims back in time about the nour belief? is it in Sunni books? is it in Sufi teachings ?Is it solid Shia beleif? Which of these schools influenced the others ?