What is the meaning of the Mu'tazilah's statement: "Allah is Knower by a knowledge which is His essence"? And is there a book that refutes the Mu'tazilah, the Jahmiyyah, and the Ash'ariyyah regarding the issue of Attributes?

The Mu'tazilah are a misguided sect that differed from the Ahl al-Sunnah on the issue of attributes. They do not affirm the essential attributes for Allah Almighty, claiming that He is knowing without knowledge, or that His knowledge is His very essence. This is to avoid, so they claim, the multiplicity of eternals and likening Allah to His creation, despite the fact that an attribute is dependent on the one described, and is eternal with His eternity, and this does not imply the blameworthy multiplicity.