Tafsir of Al-Hijr 15:94

{So proclaim that which you are commanded} Declare it openly and manifest it. It is said: "He sada'a (proclaimed) the argument" when he speaks it aloud, similar to saying "he declared it clearly." It is derived from al-sadi' (the dawn), and the sad' (crack) in a glass, which means separation/clarity.

It is also said: {So proclaim} means to separate between truth and falsehood by that which you are commanded. The meaning is "by that which you are commanded of the laws," where the preposition has been omitted, similar to the poet's saying: I commanded you to do good, so do what you were commanded.

It is also permissible for {ma} (that which) to be an infinitive particle (masdariyyah), meaning: "by your command," where the infinitive is derived from the passive voice.

{Indeed, We are sufficient for you against the mockers * Who set up another god with Allah; so they are going to know.}