Overall meaning :
Allah Almighty commends the believers who complied with the command of Allah and His Messenger, may Allah bless him and grant him peace, and readied themselves for battle again immediately after the Battle of Uhud, despite the physical and psychological wounds they had sustained following their defeat, stating that those of them who persevere in doing good and acting righteously will have a great reward. They were not dissuaded by some people’s futile attempt to intimidate them, cautioning them that the Quraysh idolaters had mustered a great force to resume their offensive against them and that they would not be able to confront them. But this threat only increased their faith and certainty and they confidently said, ‘Allah is sufficient for us and He is the best protector.’ So they returned from Hamra’ Al-Asad—to which they had previously marched to confront the idolaters—with a mighty favour and a great bounty from Allah and without suffering any harm at all at the hands of their enemies; they had indeed striven after Allah’s good pleasure by responding to the call of Allah and His Messenger, may Allah bless him and grant him peace. Allah’s grace is indeed tremendous.
The Almighty informs them that it was indeed Satan who intends to instil in their hearts fear of his supporters—the idolaters, and so He forbids them from fearing the idolaters and enjoins them to fear Him alone if they are true believers.
Allah then instructs His Prophet, Muhammad, may Allah bless him and grant him peace, not to be saddened by those who, because of their intense desire for unbelief, rush headlong into it, stressing that, by advocating unbelief, they will not harm Him in any way, and that, due to their hastening to fall into unbelief, He intends not to assign them any portion of the delights and plesures in the hereafter, stating that a grievous punishment awaits them.