Surah Fusilat (The Verses Prefectly Explained), Verse 8

اِنَّ الَّذِیْنَ اٰمَنُوْا وَعَمِلُوا الصّٰلِحٰتِ لَهُمْ اَجْرٌ غَیْرُ مَمْنُوْنٍ 

Innal lazeena aamanoo wa 'amilus saalihaati lahum ajrun ghairu mamnoon

“For those who believe and work deeds of righteousness is a reward that will never fail.”

Quran 41:8 (Yusuf Ali Translation)