Once Allah's Messenger (ﷺ) heard the loud voices of some opponents quarreling at the door. One of them was appealing to the other to deduct his debt and asking him to be lenient but the other was saying, "By Allah I will not do so." Allah's Messenger (ﷺ) went out to them and said, "Who is the one who was swearing by Allah that he would not do a favor?" That man said, "I am that person, O Allah's Messenger (ﷺ)! I will give my opponent whatever he wishes."
Sahih al-Bukhari Book 53, Hadith 15
← Previous Hadith By Allah, Al-Hasan bin `Ali led large battalions like mountains against Muawiya. `Amr bin Al-As said (to Muawiya), "I surely see battalions which will not turn back before killing their opponents." Muawiya who was really the best of the two men said to him, "O `Amr! If these killed those and those killed these, who would be left with me for the jobs of the public, who would be left with me for their women, who would be left with me for their children?" Then Muawiya sent two Quraishi men from the tribe of `Abd-i-Shams called `Abdur Rahman bin Sumura and `Abdullah bin 'Amir bin Kuraiz to Al-Hasan saying to them, "Go to this man (i.e. Al-Hasan) and negotiate peace with him and talk and appeal to him." So, they went to Al-Hasan and talked and appealed to him to accept peace. Al-Hasan said, "We, the offspring of `Abdul Muttalib, have got wealth and people have indulged in killing and corruption (and money only will appease them)." They said to Al-Hasan, "Muawiya offers you so and so, and appeals to you and entreats you to accept peace." Al-Hasan said to them, "But who will be responsible for what you have said?" They said, "We will be responsible for it." So, whatever Al- Hasan asked they said, "We will be responsible for it for you." So, Al-Hasan concluded a peace treaty with Muawiya. Al-Hasan (Al-Basri) said: I heard Abu Bakr saying, "I saw Allah's Messenger (ﷺ) on the pulpit and Al-Hasan bin `Ali was by his side. The Prophet (ﷺ) was looking once at the people and once at Al-Hasan bin `Ali saying, 'This son of mine is a Saiyid (i.e. a noble) and may Allah make peace between two big groups of Muslims through him."

Sahih al-Bukhari Book 53, Hadith 14 Next Hadith → `Abdullah bin Abu Hadrad Al-Aslami owed Ka`b bin Malik some money. One day the latter met the former and demanded his right, and their voices grew very loud. The Prophet (ﷺ) passed by them and said, "O Ka`b," beckoning with his hand as if intending to say, "Deduct half the debts." So, Ka`b took half what the other owed him and remitted the other half.

Sahih al-Bukhari Book 53, Hadith 16