30. That is the extent of their knowledge...

(That) — meaning the matter of worldly life understood from the discourse, and for this reason, the demonstrative pronoun was used. It is said: meaning what led them to the state they are in, of turning away and restricting their desire to the worldly life. It is also said: that this is a reference to the conjecture they follow. It is also said: that it refers to their designating the angels as daughters of Allah, may He be exalted; and both of these latter opinions are as you see.

(The extent of their knowledge) — meaning the limit of their knowledge, for they have no knowledge beyond it. This is an objection that affirms the content of what preceded it regarding the restriction of their desire to the worldly life. The intent by "knowledge" is the absolute perception of corrupt conjecture. The pronoun in "their extent" (mablaghuhum) refers to "those who" (man). It is pluralized in consideration of its meaning, just as it was singularized before in consideration of its wording.

And His statement, may He be glorified: (Indeed, your Lord is most knowing of who has strayed from His way, and He is most knowing of who is guided) — is a justification for the command to turn away. The repetition of His statement, "He is most knowing," is to increase confirmation and warning, due to the discrepancy between the two objects of knowledge. The intent of "who has strayed" is the one who persists in straying and does not return to guidance at all; and "who is guided" is the one whose nature is to be guided in general. Meaning: He, Glorified be His Majesty, is the One who is superlative in knowledge of those who will never desist from straying, and of those who accept guidance in general, and none other than Him. Therefore, do not weary yourself in inviting them, and do not be excessive in your eagerness for them, for they are of the first category.