Usamah bin Zaid (May Allah be pleased with them) reported:
The Messenger of Allah (ﷺ) said, "He who is favoured by another and says to his benefactor: `Jazak-Allah khairan (may Allah reward you well)' indeed praised (the benefactor) satisfactorily.''[At-Tirmidhi].
App reference: Book 17, Hadith 32
Arabic/English book reference: Book 17, Hadith 1496