Al-An'am: 88

(That), meaning this guidance to the straight path, or what is understood from the noble arrangement of the mentioned verbal sources, or what they followed as their religion. There is a meaning of distance in "that" for reasons previously repeated.

(Is the guidance of Allah): The attribution [to Allah] is for honor.

(He guides with it whom He wills): His guidance.

(Of His servants): They are those who are prepared for it. In connecting the guidance to the relative pronoun [whom], there is an indication that the content of the relative clause is the cause [for the guidance], and this implies that He, Exalted is He, is the One who bestows guidance out of grace.

(And if they had associated partners): That is, those mentioned.

(Then surely would have been invalidated): That is, nullified and collapsed.

(For them): Regarding their merit and high status.

(What they used to do): That is, the reward for their righteous deeds. So how, then, [would it be] for others besides them, while they are who they are, and their deeds are their deeds?

(Those): ...