Surah Al-A'raf 7:93

فَتَوَلَّىٰ عَنْهُمْ وَقَالَ يَـٰقَوْمِ لَقَدْ أَبْلَغْتُكُمْ رِسَـٰلَـٰتِ رَبِّى وَنَصَحْتُ لَكُمْ ۖ فَكَيْفَ ءَاسَىٰ عَلَىٰ قَوْمٍ كَـٰفِرِينَ

And he [i.e., Shuʿayb] turned away from them and said, "O my people, I had certainly conveyed to you the messages of my Lord and advised you, so how could I grieve for a disbelieving people?"

Translation: Saheeh International

Tafsir

So he turned back on them and said ‘O my people I have conveyed to you the Messages of my Lord and advised you sincerely but you believe not so why should I grieve for a disbelieving people?’ the interrogative is meant rhetorically as a negation.

Excerpt from Tafsir al-Jalalayn, commentary on 7:93, via Quran.com. The reader has the full commentary and 9 more tafsirs.