Surah 36

Surah 36:10

"(It is) the same for them whether you warn them or you do not warn them. They will not believe."

36.10 – (It is) the same for them whether you warn them or you do not warn them
This verse indicates the limitations of preaching and perhaps also signals that the preacher is losing hope.

- from The Quran with Christian Commentary: A Guide to Understanding the Scripture of Islam