[3:166-167] And what afflicted you, the day the two hosts encountered, was by God's leave, and that He might know the believers. * And that He might also know the hypocrites when it was said to them, 'Come now, fight in the way of God or defend', they said, 'If we knew how to fight we would follow you'. They that day were nearer to unbelief than to belief, saying with their mouths that which was not in their hearts. And God knows best what they hide.
He lightened the grave calamity the believers and possessors of insight met on the Day of Uḥud by saying that that encounter was by God's leave. Surely a trial that afflicts by God's leave is sweeter than honey and more desirable than any blessing. Then He spoke of those who were not sincere comrades, how they offered excuses and were lazy:
Similarly, when the one who is tired
wants to break things off
He becomes weary of being together
and says, 'That was that'.
Saying with their mouths that which was not in their hearts: Verily they gave honey to drink but plotted to put poison in it for him. They plotted and God plotted and God was aware of those who plotted.