﴿ ٱتَّخَذُوٓا۟ أَيْمَٰنَهُمْ جُنَّةًۭ فَصَدُّوا۟ عَن سَبِيلِ ٱللَّهِ ۚ إِنَّهُمْ سَآءَ مَا كَانُوا۟ يَعْمَلُونَ ﴾

“They have made their oaths a cover [for their falseness], and thus they turn others away from the Path of God. Evil indeed is all that they are wont to do:”

They have taken their oaths as a shield as a means of protection for their possessions and their lives and so they have barred thereby from the way of God that is from using them for the struggle. Evil indeed is that which they are wont to do.