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." (Using translation from Tirmidhī 2035)  

قَالَ رَسُولُ اللهِ ﷺ مَنْ صُنِعَ إِلَيْهِ مَعْرُوفٌ فَقَالَ لِفَاعِلِهِ جَزَاكَ اللهُ خَيْرًا فَقَدْ أَبْلَغَ فِي الثَّنَاءِ  

[Machine] The immigrants said, "O Messenger of Allah, the Ansar have given all of their reward. We have not seen a people who excel in giving a lot and in comforting a few of them. And we have been sufficient in sustenance." He said, "Are you not grateful to them and pray to Allah for them?" They said, "Yes." He said, "That is in return for that."  

قَالَتِ الْمُهَاجِرُونَ يَا رَسُولَ اللهِ ذَهَبْتِ الْأَنْصَارُ بِالْأَجْرِ كُلِّهِ مَا رَأَيْنَا قَوْمًا أَحْسَنَ بَذْلًا لَكَثِيرٍ وَلَا أَحْسَنَ مُوَاسَاةٍ فِي قَلِيلٍ مِنْهُمْ وَلَقَدْ كَفَوْنَا الْمُؤْنَةَ؟ قَالَ «أَلَيْسَ تُثْنُونَ عَلَيْهِمْ بِهِ وَتَدْعُونَ اللهَ لَهُمْ؟» قَالُوا بَلَى قَالَ «فَذَاكَ بِذَاكَ»