Overall meaning : Allah Almighty instructs his Messenger, may Allah bless him and grant him peace, to enjoin the believers not to take the disbelievers as allies and supporters and say to them: Whether you keep good or evil, amity or enmity hidden in in your hearts and minds, or bring all that to the open by word or deed, it is all known to Allah, and He will surely call you to account for everything and repay you according to your deeds; for His unbounded knowledge encompasses all that is in the heavens and all that is on earth, and nothing is hidden from Him. He is omnipotent and nothing in the heavens or on earth can possibly resist His will.
Next, He mentions the appointed time when reward or punishment will take place. It is the Day of Judgement, He declares, when everyone will find himself confronted with a full and detailed account of all the good deeds he has done, whether good and evil, little or much, without having been subjected to any alteration whatsoever. As for his evil deeds, he will wish that there were a great distance between him and them. Allah then stresses His warning to His servants to guard against His wrath and to fear His punishment, and explains to them that it is only because of His great mercy and compassion towards them that He warns them.