Overall meaning : Regarding those who substitute unbelief for faith, Allah Almighty states that by so doing they will not do the least harm to Him and that they will have an exceedingly grievous punishment.
Allah then tells His Prophet, Muhammad, may Allah bless him and grant him peace, as well as the unbelievers, not to entertain the thought that, by letting the unbelievers enjoy the worldly life and not hastening their punishment, He intends good for them; rather, He gives them respite so they may commit more grievous sins, and they will suffer a disgraceful punishment.
Then, addressing Muslims, He states that it is not wise and right in His sight to leave them in the state in which they are—undistinguishable from the hypocrites: He has to put them to the test to distinguish the corrupt from the pure.
Nor does He deem it wise and right that He should make anyone aware of the thoughts and intents of people’s minds and hearts to distinguish the believers from the hypocrites. Rather, He uses trials for this purpose. But Allah does choose some of His messengers, peace and blessings be upon them, to whom He reveals some of the hidden secrets that are beyond the reach of human perception, all in His wisdom and by His permission. Allah then commands the faithful to stand firm in their belief in Him and all His messengers, assuring them that if they do so and do what He commands and avoid what He forbids, they will surely receive a great reward.
Allah then addresses His Prophet, Muhammad, may Allah bless him and grant him peace, telling him not to suppose that the niggardliness of those who greedily withhold the wealth that Allah has granted them out of His bounty is better for them than spending from it. Allah equally addresses those who are tight-fisted with their wealth, telling that they should not think that withholding is better for them than giving; on the contrary, it will be evil for them; for Allah has warned those who niggardly withhold their wealth and do not remit Allah’s portion which He has ordained as obligatory charity (zakat) that He will punish them with such wealth by having it tied to their necks like a twisted collar on the Day of Judgement. He further states that He is the sole possessor of the heavens and the earth, and all property He has granted them will ultimately be returned to Him after they all perish, and that He is fully aware of what everyone does.