Hadith on Kufr: Unbelievers rewarded in this life only

Anas ibn Malik reported: The Messenger of Allah, peace and blessings be upon him, said, “Verily, when the unbeliever performs a good deed, he is given a taste of its reward in the world. As for the believer, Allah will store his good deeds for him in the Hereafter and provide his sustenance in the world, due to his obedience.”

Source: Ṣaḥīḥ Muslim 2808

Grade: Sahih (authentic) according to Muslim

عَنْ أَنَسِ بْنِ مَالِكٍ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِنَّ الْكَافِرَ إِذَا عَمِلَ حَسَنَةً أُطْعِمَ بِهَا طُعْمَةً مِنْ الدُّنْيَا وَأَمَّا الْمُؤْمِنُ فَإِنَّ اللَّهَ يَدَّخِرُ لَهُ حَسَنَاتِهِ فِي الْآخِرَةِ وَيُعْقِبُهُ رِزْقًا فِي الدُّنْيَا عَلَى طَاعَتِهِ

2808 صحيح مسلم كتاب صفة القيامة والجنة والنار باب جزاء المؤمن بحسناته في الدنيا والآخرة وتعجيل حسنات الكافر في الدنيا