﴿ إِنَّ ٱللَّهَ لَا يَظْلِمُ مِثْقَالَ ذَرَّةٍۢ ۖ وَإِن تَكُ حَسَنَةًۭ يُضَٰعِفْهَا وَيُؤْتِ مِن لَّدُنْهُ أَجْرًا عَظِيمًۭا ﴾

“Verily, God does not wrong [anyone] by as much as an atom's weight; and if there be a good deed, He will multiply it, and will bestow out of His grace a mighty reward.”

Please check ayah 4:42 for complete tafsir.