That ʿAbdullah bin Abi Hadrad Al-Aslami owed him some debt. Kaʿb met him and caught hold of him and they started talking and their voices grew loudest. The Prophet ﷺ passed by them and addressed Kaʿb, pointing out to him to reduce the debt to one half. So, Kaʿb got one half of the debt and exempted the debtor from the other half. (Using translation from Bukhārī 2424)  

أَنَّهُ كَانَ لَهُ عَلَى عَبْدِ اللهِ بْنِ أَبِي حَدْرَدٍ الْأَسْلَمِيِّ دَيْنٌ فَلَقِيَهُ فَلَزِمَهُ فَتَكَلَّمَا حَتَّى ارْتَفَعَتِ الْأَصْوَاتُ فَمَرَّ بِهِمَا رَسُولُ اللهِ ﷺ فَقَالَ «يَا كَعْبُ» فَأَشَارَ بِيَدِهِ كَأَنَّهُ يَقُولُ النِّصْفُ فَأَخَذَ نِصْفًا مِمَّا عَلَيْهِ وَتَرَكَ نِصْفًا