Tafsir of Yunus 10:13

{And We had already destroyed generations...}

{When} is an adverbial of time for "We destroyed." The waw in {and their messengers had come to them} is for the state (ḥāl), meaning: they committed injustice by denying [the truth], while their messengers had already come to them with proofs and evidence of their truthfulness, which are the miracles.

Regarding His saying: {and they were not to believe}:

• It is permissible for it to be a conjunction linked to "they committed injustice."
• It is also permissible for it to be a parenthetical clause.
• The lām is for the emphasis of negation. It means: they would not truly believe, as an emphasis on the negation of their faith, and that God knew they would persist in their disbelief, and that faith was far-removed from them.

The meaning is: The reason for their destruction was their denial of the messengers, and God’s knowledge that there was no benefit in granting them respite after the proof had been established against them by sending the messengers.

{Thus}: Like that recompense—meaning destruction—{do We recompense} every criminal. This is a threat to the people of Mecca for their criminality in denying the Messenger of God, may God bless him and grant him peace. It is also read as yujzā (in the passive voice).

{Then We made you}: The address is to those to whom Muhammad, may God bless him and grant him peace, was sent. Meaning: We made you successors on the earth after the generations We destroyed.

{That We may observe}: Whether you will do good or evil, so that We may treat you according to your deeds.

{How} is in the accusative position governed by taʿmalūn (you do), not yanzur (observe), because the interrogative meaning within it prevents its governing verb from preceding it.

If you ask: How is "observation" (naẓar) permissible for God Almighty, when it implies the meaning of confrontation? I say: It is a metaphor for verified knowledge—which is knowledge of a thing as it exists—likened to the observation of an observer and the witnessing of a witness in its certainty.

{And when Our verses are recited to them as clear evidences, those who do not expect the meeting with Us say, "Bring a Qur'an other than this or change it." Say, "It is not for me to change it on my own accord. I only follow what is revealed to me. Indeed I fear, if I should disobey my Lord, the punishment of a tremendous Day."}