Surah Al-Hajj — Ayah 71 (22:71)
وَيَعۡبُدُونَ مِن دُونِ ٱللَّهِ مَا لَمۡ يُنَزِّلۡ بِهِۦ سُلۡطَٰنٗا وَمَا لَيۡسَ لَهُم بِهِۦ عِلۡمٞۗ وَمَا لِلظَّٰلِمِينَ مِن نَّصِيرٖ ٧١
English translation (Saheeh International)
And they worship besides Allāh that for which He has not sent down authority and that of which they have no knowledge. And there will not be for the wrongdoers any helper.
Brief commentary
The idolaters worship idols instead of Allah; idols which Allah did not reveal any proof of their worship being acceptable in His books. Neither do they have any proof of their own knowledge; their only object of reliance for that is blind following of their forefathers. The wrongdoers will have no helper that will protect them from the punishment of Allah that will fall upon them.