﴿ فَعَقَرُوهَا فَأَصْبَحُوا۟ نَٰدِمِينَ ﴾

“But they cruelly slaughtered her - and then they had cause to regret it:”

But they hamstrung her — a group of them hamstrung her with the approval of others; and then became remorseful for having hamstrung it.