Hadith: Arabic Text followed by English Translation.
عَنْ أُسَامَةَ بْنِ زَيْدٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم
مَنْ صُنِعَ إِلَيْهِ مَعْرُوفٌ فَقَالَ لِفَاعِلِهِ جَزَاكَ اللَّهُ خَيْرًا فَقَدْ أَبْلَغَ فِي الثَّنَاءِ
((رواه الترمذي ٢٠٣٥ وصححه الألباني في صحيح الترمذي )
Usamah bin Zaid narrated that the Messenger of Allah (ﷺ) said:
Whoever some good was done to him, and he says: ‘May Allah reward you in goodness’ then he has done the most that he can of praise
Jami` at-Tirmidhi 2035 classed as Saheeh by Albani in Saheeh Tirmidhi.