Surah Al-Hujurat 49:6

يَـٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓا۟ إِن جَآءَكُمْ فَاسِقٌۢ بِنَبَإٍ فَتَبَيَّنُوٓا۟ أَن تُصِيبُوا۟ قَوْمًۢا بِجَهَـٰلَةٍ فَتُصْبِحُوا۟ عَلَىٰ مَا فَعَلْتُمْ نَـٰدِمِينَ

O you who have believed, if there comes to you a disobedient one with information, investigate, lest you harm a people out of ignorance and become, over what you have done, regretful.

Translation: Saheeh International

Tafsir

The following was revealed regarding al-Walīd b. ‘Uqba whom the Prophet had sent to the Banū al-Mustaliq in order to ascertain their loyalty to Islam. He already feared them on account of an old feud between him and them from the time of pagandom before Islam and so upon seeing them come out to him he returned and …

Excerpt from Tafsir al-Jalalayn, commentary on 49:6, via Quran.com. The reader has the full commentary and 9 more tafsirs.