It is narrated from Abu al-Ma'arik (may Allah have mercy on him) that a man from the tribe of Ghafiq was owed one hundred dinars by a man from the tribe of Mahrah in the time of Uthman (may Allah be pleased with him). Then they obtained good spoils of war, and the Mahri said: "I will give you seventy dinars right away on the condition that you write off the hundred dinars I owe you." Those hundred dinars had been a cause of dispute. The Ghafiqi agreed to that. Then Sayyiduna al-Miqdad (may Allah be pleased with him) passed by them, and he (the Ghafiqi) took hold of the reins of his mount so that he would act as a witness. When the whole affair was related to him, he said: "Both of you have been given notice of war from Allah and His Messenger."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17731