﴿ تَٱللَّهِ لَقَدْ أَرْسَلْنَآ إِلَىٰٓ أُمَمٍۢ مِّن قَبْلِكَ فَزَيَّنَ لَهُمُ ٱلشَّيْطَٰنُ أَعْمَٰلَهُمْ فَهُوَ وَلِيُّهُمُ ٱلْيَوْمَ وَلَهُمْ عَذَابٌ أَلِيمٌۭ ﴾

“By God, [O Prophet,] even before thy time have We sent apostles unto [various] communities: but [those who were bent on denying the truth have always refused to listen to Our messages because] Satan has made all their own doings seem goodly to them: and he is [as] close to them today [as he was to the sinners of yore]; hence, grievous suffering awaits them.”

By God We verily sent to communities before you messengers. But Satan adorned for them their deeds their evil deeds so that they considered them to be good deeds and therefore they denied the messengers. So he is their patron the guardian of their affairs today that is now in this world and for them there will be a painful chastisement in the Hereafter. It is also said that by al-yawm ‘today’ is meant the Day of Resurrection narrating the events as though they are taking place now. In other words they have no guardian other than him in other words Satan and as he is incapable of helping himself how could he possibly help them?