Surah Hud 11:26

أَن لَّا تَعْبُدُوٓا۟ إِلَّا ٱللَّهَ ۖ إِنِّىٓ أَخَافُ عَلَيْكُمْ عَذَابَ يَوْمٍ أَلِيمٍ

That you not worship except Allāh. Indeed, I fear for you the punishment of a painful day."

Translation: Saheeh International

Tafsir

That you worship none but God. Lo! I fear for you should you worship other than Him the chastisement of a painful day’ painful in this world and in the Hereafter.

Excerpt from Tafsir al-Jalalayn, commentary on 11:26, via Quran.com. The reader has the full commentary and 9 more tafsirs.