"During the year of the Farewell Pilgrimage, I heard the Prophet (ﷺ) saying during the Khutbah: "The borrowed is to be returned, and the guarantor is responsible, and the debt is to be repaid."

There are narrations on this topic from Samurah, Safwan bin Umayyah, and Anas.

The Hadith of Abu Umamah is a Hasan Gharib Hadith. It has also been reported through other routes besides this, from Abu Umamah, from the Prophet (ﷺ).

Jami` at-Tirmidhi Book 14, Hadith 67