These are matters such as lying and betrayal. Secondly: Knowledge of what must be denied of him.

Thirdly: Knowledge of what is permissible for him. Such as ease and hardship, and forgetfulness that does not incur obligation.

Obligation.

C. Knowledge of what the Messenger brought. It is of three types: Firstly: Knowledge of revelation (which is God's command, prohibition, and news).

Secondly: Knowledge of obligation. It is the implication of command and prohibition.

Thirdly: Knowledge of reward for obligation. It is reckoning, reward, and punishment.

Knowledge of the world: It is of three types: A. Knowledge of its benefits. B. Knowledge of its harms.

C. Knowledge of the means of livelihood.

What leads to knowledge of things: It is of three types: A. Language. If language is invalid, the Sharia is invalid.

B. Grammar. If grammar is invalid, meanings are invalid. If meanings are invalid, the law is invalid.

C. Calculation. It is also what leads to knowledge of religion, such as prayer and zakat, and the world in all other dealings. It is therefore a great foundation in religion.

We ourselves.

Muslims have paid attention from an early time to the science of classifying sciences (or the science of divisions).

And thereafter. (See the detail of this division in: Ibn Tumart - Risala fi al-'Ilm: 15) 167