Surah Al-Qasas 28:86

وَمَا كُنتَ تَرْجُوٓا۟ أَن يُلْقَىٰٓ إِلَيْكَ ٱلْكِتَـٰبُ إِلَّا رَحْمَةً مِّن رَّبِّكَ ۖ فَلَا تَكُونَنَّ ظَهِيرًا لِّلْكَـٰفِرِينَ

And you were not expecting that the Book would be conveyed to you, but [it is] a mercy from your Lord. So do not be an assistant to the disbelievers.

Translation: Saheeh International

Tafsir

And you never expected that the Scripture the Qur’ān would be conferred on you; but it was conferred on you as a mercy from your Lord. So never be a supporter of the disbelievers in that religion of theirs to which they summon you.

Excerpt from Tafsir al-Jalalayn, commentary on 28:86, via Quran.com. The reader has the full commentary and 9 more tafsirs.