How did Ibn Abd al-Wahhab deduce that celebrating the Mawlid is unlawful, and what is the jurisprudential evidence for that?

We have previously emphasized that our role is in issuing fatwas, not in conducting research or discussions, and that the questioner must be the first to adhere to the academic methodology. His statement contained clear fallacies, especially his stance on Sheikh Muhammad ibn Abd al-Wahhab, despite the availability of his books. We highlight two examples to demonstrate adherence to the academic methodology:

First: His claim that Ibn Taymiyyah abandoned the concept of bid'ah (innovation) in "Iqtidha' al-Sirat al-Mustaqim" and affirmed that bid'ah can be good or bad. This indicates that he has not read the book; for Sheikh al-Islam established the general dispraise of every religious innovation, and clarified that the hadith (definition) "Every innovation is misguidance" cannot be refuted, and whatever is proven to be good is not an innovation, or it is a specific exception from the general rule based on a legitimate religious proof.

Second: His reliance on the verse: "And monasticism, which they innovated" to argue that Allah accepted the innovation of monasticism from the Christians. Ibn Kathir interpreted the verse to mean that Allah condemned them for innovating in religion and for not fulfilling what they committed themselves to.