{And if He had shown them to you as many, you would have lost courage} meaning: you would have become cowardly. {And would have disputed in the matter} meaning: you would have disagreed regarding the command of Allah and His Messenger. {But Allah saved [you]} from that.

{Indeed, He} meaning Allah, {is Knowing of that within the breasts} meaning: of what is contained within them. He says: By virtue of His knowledge of what is in your breasts, He made them appear few in your eyes and removed the fear that was in your breasts.