Surah Al-A'raf 7:188

قُل لَّآ أَمْلِكُ لِنَفْسِى نَفْعًا وَلَا ضَرًّا إِلَّا مَا شَآءَ ٱللَّهُ ۚ وَلَوْ كُنتُ أَعْلَمُ ٱلْغَيْبَ لَٱسْتَكْثَرْتُ مِنَ ٱلْخَيْرِ وَمَا مَسَّنِىَ ٱلسُّوٓءُ ۚ إِنْ أَنَا۠ إِلَّا نَذِيرٌ وَبَشِيرٌ لِّقَوْمٍ يُؤْمِنُونَ

Say, "I hold not for myself [the power of] benefit or harm, except what Allāh has willed. And if I knew the unseen, I could have acquired much wealth, and no harm would have touched me. I am not except a warner and a bringer of good tidings to a people who believe."

Translation: Saheeh International

Tafsir

Say ‘I have no power to bring benefit to attract it to myself or hurt to repel it except as God wills. Had I knowledge of the Unseen — that which is hidden from me I would have acquired much good and adversity in the way of impoverishment and otherwise would not touch me since I would take precautions against such …

Excerpt from Tafsir al-Jalalayn, commentary on 7:188, via Quran.com. The reader has the full commentary and 9 more tafsirs.