"Our Lord! Cause them to suffer the punishment doubled, and curse them with a mighty curse (so that they are utterly excluded, absolutely and eternally, from Your Mercy)!"
“Our Rabb, give them double suffering and curse them with a mighty curse.”
Sayyed Abbas Sadr-Ameli
O' our Lord! Give them double chastisement and curse them with a great curse
Al-muntakhab fi tafsir al-Qur'an al-Karim
O Allah, our Creator "they add" We implore You and We beg You to afflict them with double the torment and to consign them to evil and to pour upon them unbearable loads of maledictions