Sura 3 Ali 'Imran (Family of Imran), ayah 171

1. يَسْتَبْشِرُونَ بِنِعْمَةٍ مِنَ اللَّهِ وَفَضْلٍ وَأَنَّ اللَّهَ لَا يُضِيعُ أَجْرَ الْمُؤْمِنِينَ

   They receive good tidings of favor from Allah and bounty and (of the fact) that Allah does not allow the reward of believers to be lost -

   3:171

Translation: Saheeh International