But they killed her and made way for their own humiliation. (The usual rendering here of FAASBAHOO NADIMEEN that they regretted, repented or became penitent seems to be incorrect, since in that case the Most Gracious might have forgiven them)
(Taking no heed of this warning) they viciously slaughtered her; and became very regretful.
Sayyed Abbas Sadr-Ameli
Then they hamstrung her, and became regretful
Al-muntakhab fi tafsir al-Qur'an al-Karim
Nevertheless they defiantly disabled her by cutting her hamstring muscles. (Their outrage on consecrated objects invited their ruin) which led to pining regrets and vain repentances