Surah Al-A'raf 7:177

سَآءَ مَثَلًا ٱلْقَوْمُ ٱلَّذِينَ كَذَّبُوا۟ بِـَٔايَـٰتِنَا وَأَنفُسَهُمْ كَانُوا۟ يَظْلِمُونَ

How evil an example [is that of] the people who denied Our signs and used to wrong themselves.

Translation: Saheeh International

Tafsir

Evil as an example are the people evil is the example of the people who denied Our signs and were wont to wrong themselves through denial.

Excerpt from Tafsir al-Jalalayn, commentary on 7:177, via Quran.com. The reader has the full commentary and 9 more tafsirs.