Allah said,
(But have denied it) denied the Qur'an, guidance and clear explanation that you (O Muhammad ) have brought them,
(your people) meaning, Quraysh,
(though it is the truth.) beyond which there is no other truth.
(Say: "I am not responsible for your affairs.") meaning, I have not been appointed a guardian or watcher over you. Allah also said;
(And say: "The truth is from your Lord." Then whosoever wills, let him believe, and whosoever wills, let him disbelieve.) 18:29, This means, my duty is to convey the Message and your duty is to hear and obey. Those who follow me, will acquire happiness in this life and the Hereafter. Those who defy me will become miserable in this life and the Hereafter. So Allah said;
(For every news there is a reality...) meaning, for every news, there is a reality, in that, this news will occur, perhaps after a while, according to Ibn `Abbas and others. Allah said in other Ayat,
(And you shall certainly know the truth of it after a while.) 38:88 and,
((For) each and every matter there is a decree (from Allah).) 13:38. This, indeed, is a warning and a promise that will surely occur,
(and you will come to know.) Allah's statement,
(And when you see those who engage in false conversation about Our verses (of the Qur'an)), by denying and mocking them.
(stay away from them till they turn to another topic.) until they talk about a subject other than the denial they were engaged in.
(And if Shaytan causes you to forget...) This command includes every member of this Ummah. No one is to sit with those who deny and distort Allah's Ayat and explain them incorrectly. If one forgets and sits with such people,
(then after the remembrance sit not you) after you remember,
(in the company of those people who are the wrongdoers.). A Hadith states,
(My Ummah was forgiven unintentional errors, forgetfulness and what they are coerced to do.) The Ayah above 6:68 is the Ayah mentioned in Allah's statement,
(And it has already been revealed to you in the Book that when you hear the Verses of Allah being denied and mocked at, then sit not with them, until they engage in a talk other than that; (but if you stayed with them) certainly in that case you would be like them.) 4:140, for, if you still sit with them, agreeing to what they say, you will be just like them. Allah's statement,
(There is no responsibility for them upon those who have Taqwa,) means, when the believers avoid sitting with wrongdoers in this case, they will be innocent of them and they will have saved themselves from their sin. Allah's statement,
(but (their duty) is to remind them, that they may avoid that.), means, We commanded you to ignore and avoid them, so that they become aware of the error they are indulging in, that they may avoid this behavior and never repeat it again.