Allah states that He has cursed the disbelievers among the Children of Israel long ago, and revealed this fact to His Prophets Dawud and `Isa, son of Maryam. He cursed them because they disobeyed Allah and transgressed against His creatures. Al-`Awfi reported that Ibn `Abbas said, "They were cursed in the Tawrah, the Injil, the Zabur (Psalms) and the Furqan (Qur'an).'' Allah then states that during their time, their habit was that,

﴿كَانُواْ لاَ يَتَنَـهَوْنَ عَن مُّنكَرٍ فَعَلُوهُ﴾

(They used not to forbid one another from the evil they committed.) They did not forbid each other from committing sins and the prohibitions. Allah chastised them for this behavior, so that their behavior would not be imitated. Allah said,

﴿لَبِئْسَ مَا كَانُواْ يَفْعَلُونَ﴾

(Vile indeed was what they used to do.)