Yā Sīn 36:10

وَسَوَآءٌ عَلَيْهِمْ ءَأَنذَرْتَهُمْ أَمْ لَمْ تُنذِرْهُمْ لَا يُؤْمِنُونَ ﴿١٠﴾

It is the same to them whether you warn them or do not warn them, they will not have faith.

Exegesis

The interpretation of this verse was discussed in 2:6, which is similar to this verse.