18 In vv. 9-27 an appraisal has been made of the Battle of the Trench and the raid against the Bani Quraiz, ah and were revealed at the end of the raid. One should keep the details of these events in view as given in the Introduction above.
19 The windstorm did not lash the enemy hordes immediately on their arrival but it occurred when the siege of Madinah had lasted about a month. "Armies which you could not see" implies the hidden powers which operate in the affairs of men under Allah's Command and of which men are wholly unaware. Man regards the occurrence of events and incidents as resulting from apparent causes and does not take into account the hidden forces at work, whereas in most cases these very hidden forces play the decisive role. As these forces function under the Command of Allah's angels, the "armies" may imply the angels as well though there is no indication here of sending the armies of the angels.