Overall meaning : Allah gives comfort to the Muslims after the defeat they suffered at the Battle of Uhud, explaining that His immutable ways and laws, which He has established for human communities, operated even before their time, and urges them to travel through the land to see for themselves the terrible fate of the unbelievers.
The Almighty then points out that the Holy Qur’an is a clear statement to all mankind: It shows them how to distinguish truth from falsehood, leads the righteous to the right path and helps prevent them from following the path of error and corruption.
Next, He admonishes the Muslims not to lose heart nor fall into despair and be overcome by grief because of the defeat they have faced, for they will always be superior to their enemies and will have the upper hand as long as they firmly adhere to their faith. If they have suffered casualties and received wounds, their enemies have already suffered casualties and injuries at the Battle of Uhud, and so they are even now and should not let grief get the better of them. Indeed, this reveals one of Allah’s immutable ways and laws in this world: The days of fortune and misfortune alternate between all people, believers and unbelievers alike. Sometimes they achieve victory, and at other times they suffer defeat. Such days of varying fortunes are governed by divine laws. In this way, Allah distinguishes the true believers from the false ones and honours some of them with martyrdom while fighting for His religion. Allah does not love the wrongdoers. As a result of the defeat the Muslims faced at Uhud, Allah further states, He intends to cleanse them of their sins through the killing and wounds they suffered, to rid them of the hypocrites in their midst and to destroy the unbelievers.