Surah Al-An'am 6:147

فَإِن كَذَّبُوكَ فَقُل رَّبُّكُمْ ذُو رَحْمَةٍ وَٰسِعَةٍ وَلَا يُرَدُّ بَأْسُهُۥ عَنِ ٱلْقَوْمِ ٱلْمُجْرِمِينَ

So if they deny you, [O Muḥammad], say, "Your Lord is the possessor of vast mercy; but His punishment cannot be repelled from the people who are criminals."

Translation: Saheeh International

Tafsir

So if they deny you with regard to what you have brought then say to them ‘Your Lord has all-embracing mercy for He does not hasten to bring about your punishment — herein is a gentle summoning of them to the faith; and His might His chastisement when it comes will never be driven back from the sinning folk’.

Excerpt from Tafsir al-Jalalayn, commentary on 6:147, via Quran.com. The reader has the full commentary and 9 more tafsirs.