Overall meaning : Remember, Muhammad, when your Lord inspired the angels, saying that He was with them, giving them assistance and support, and commanded them to help fortify their resolve of the believers, stating that He would strike terror into the hearts of the unbelievers, and directed them to strike off the idolaters’ heads and the very tips of their fingers and toes.
That is, He explains, because they have disobeyed the commands of Allah and His Messenger and opposed them, adding that He will punish whoever does so, and states that His punishment is severe indeed.
This is your punishment in this life, O unbelievers. Taste it, then, and know for sure that you, and other unbelievers, will suffer the eternal punishment of Hell in the life to come.