Sahih Muslim 2687 b
A hadith like this has been transmitted on the authority of A'mash with the same chain of transmitters and he (further) said:
There is for him ten like that (the good he performed) or more than that.
حَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، بِهَذَا الإِسْنَادِ ‏.‏ نَحْوَهُ غَيْرَ
 أَنَّهُ قَالَ ‏
"‏ فَلَهُ عَشْرُ أَمْثَالِهَا أَوْ أَزِيدُ ‏"‏ ‏.‏