ذَٰلِكَ أَن لَّمۡ يَكُن رَّبُّكَ مُهۡلِكَ ٱلۡقُرَىٰ بِظُلۡمٖ وَأَهۡلُهَا غَٰفِلُونَ ١٣١
That is because your Lord would not destroy the cities for wrongdoing1 while their people were unaware.
Translation: Saheeh International (English)
1 Or "unjustly."
Each word's meaning and sound
The reason for sending messengers to mankind and jinn is so that no one is punished for the crimes they committed without a messenger having been sent to warn them and the invitation reaching them. I only punished a nation after sending messengers to them.
Al-Mukhtasar in interpreting the Noble Quran