Sahih Muslim Book - 50, Hadith - 7090

حَدَّثَنَا عَاصِمُ بْنُ النَّضْرِ التَّيْمِىُّ حَدَّثَنَا مُعْتَمِرٌ قَالَ سَمِعْتُ أَبِى حَدَّثَنَا قَتَادَةُ عَنْ أَنَسِ بْنِ مَالِكٍ أَنَّهُ حَدَّثَ عَنْ رَسُولِ اللَّهِ -صلى الله عليه وسلم- « إِنَّ الْكَافِرَ إِذَا عَمِلَ حَسَنَةً أُطْعِمَ بِهَا طُعْمَةً مِنَ الدُّنْيَا وَأَمَّا الْمُؤْمِنُ فَإِنَّ اللَّهَ يَدَّخِرُ لَهُ حَسَنَاتِهِ فِى الآخِرَةِ وَيُعْقِبُهُ رِزْقًا فِى الدُّنْيَا عَلَى طَاعَتِهِ ».

It was narrated from Anas bin Malik from the Messenger of Allah (s.a.w): "If the disbeliever does a good deed, he is fed because of it in this world. As for the believer, Allah stores up his good deeds for him in the Hereafter, and grants him provision in accordance with his obedience in this world."