Tafsir of Al-Qalam 68:7

{Indeed, your Lord is most knowing} of those who are truly mad, who have strayed from His path, {and He is most knowing} of the wise, who are the guided. Alternatively, it is a threat and a promise, meaning He is most knowing of the recompense for both groups.

{So do not obey the deniers} This is an incitement and a provocation to remain firm in opposing them. They had wanted him to worship Allah for a time and their gods for a time, so that they would cease their harm against him.

{If you were to compromise (tudhin), they would compromise (yudhinun)} If you were to soften and flatter, they would soften and flatter.

If you ask: Why is yudhinun in the nominative case (marfu‘) rather than the subjunctive (mansub) by an implied an, given that it is the response to a wish (tamanni)?

I say: It has been diverted to another path: it is made the predicate of an omitted subject, meaning: "Then they are compromising." It is like the Almighty’s saying: {So whoever believes in his Lord will not fear} (Al-Jinn: 13). The meaning is: They wished that you would compromise, and they are therefore compromising. Or: They wished for your compromise, and they are now compromising because of their greed for your compromise. Sibawayh said: Harun claimed that in some codices it is written: waddū law tudhinu fayadhinū (in the subjunctive).

{And do not obey every worthless habitual swearer, a backbiter, going about with gossip, a preventer of good, a transgressor, a sinner, cruel, and moreover, an illegitimate child. [It is] because he possesses wealth and children. When Our verses are recited to him, he says, "Legends of the former peoples." We will brand him upon the snout.}