among you, seeking to sow discord among you; and among you are those who would listen to them.”
[Surah al-Tawbah: 47]

And He said:

“As for those in whose hearts is deviation, they follow what is ambiguous in it, seeking discord and seeking its interpretation.”
[Surah Āl ʿImrān: 7]

You will find leading scholars among the people of innovation and division—both believers and hypocrites—writing on these matters for kings and ministers who wield military power and wealth. They seek their favor by composing works that accord with their views. Thus, al-Karkhī wrote a book on the permissibility of nabīdh for one of the rulers. Al-Jāhiz had written a book before him, though I believe his was general in scope. Likewise, Ibn Fūrak wrote a book on the doctrine of Ibn Kullāb