Jami at-Tirmidhi — The Book on Business — Hadith No: 1265
Translation
Narrated Abu Umamah: "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." [Abu 'Eisa said:] There are narrations on this topic from Samurah, Safwan bin Umayyah, and Anas. [He said:] 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)