It is narrated from Hazrat Aisha (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) said: Whoever has received a favor from someone should repay it, and whoever is unable to do so should at least mention it in a good manner, for mentioning it in a good manner is also a way of expressing gratitude. And whoever pretends to be satisfied with something he has not received is like one who wears two garments of falsehood.
Hadith Referenceمسند احمد / مسند النساء / 24593
Hadith Gradingحکم دارالسلام:قوله : من تشيع ... صحيح، وبقية الحديث حسن لغيره، وهذا إسناد ضعيف لضعف صالح بن أبى الأخضر