Overall meaning : We did not send down angels from the heavens to destroy that believing man’s people after they had killed him, for there was no need to send them down. Their punishment was but one single mighty blast, and they fell down lifeless! Alas for the unbelieving people on Judgement Day when they perceive the punishment! No messenger comes to them without their mocking him!
Do these idolaters not see how many nations We have destroyed before them for their persisting in their unbelief and mocking their messengers, and that those destroyed never return to them?! Yet all nations will be brought before Us on Resurrection Day so that We repay them for their deeds.