So, what is the basis of the category, ?Wajib?, and when was it introduced? Is it supported by all Schools of Thought, and why?
The word ‘Waajib’ is an Academic term with a specific clarification.
It is a category of compulsion which is proven with Qatiuss suboot
(expressly proven) and Zaniyyat dalaalah (indirectly indicative) or Qatiyyu
ad-dalaalah (expressly indicative) and Zaniyyat as-suboot (indirectly
proven).
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai