It is narrated from Yahya bin Abdullah bin Sayfi that the Messenger of Allah (peace and blessings be upon him) said: "Whoever receives a blessing from Allah Almighty through me, it is binding upon him to repay it; then if he does not have the means to repay it, let him express abundant praise and commendation (of the benefactor); and if he does not do even that, he has certainly been ungrateful (for the blessing)."
This report is mursal; Imam Ahmad narrated it in al-Musnad, and its basis is established on the strength of other supporting reports.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب الأدب / 2613
Hadith Gradingمحدثین:إسناده مرسل
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :مرسل. » «انفرد به المصنف من هذا الطريق»