Mercy and Forgive
Forgiving someone improves their Manners
Az-Zubair رضي الله عنه (May Allah be pleased with him) said: Allah ordered His Prophet صلى الله عليه وسلم (Peace be upon him) to Forgive the people so that their Manners become Better.
[Sahi Bukhari, Hadith no. 4644]
Show Mercy, Receive Mercy
Narrated Abdullah ibn Amr ibn al−As رضي الله عنه (May Allah be pleased with him): The Prophet صلى الله عليه وسلم (Peace be upon him) said: The Compassionate One(Allah) has mercy on those who are merciful. If you show mercy to those who are on the earth, He Who is in the heaven will Show Mercy to you.
[Sunan Abu Dawood, Hadith no. 4941, Authentic]
Who is Miserable?
Narrated Abu Huraira رضي الله عنه (May Allah be pleased with him): I heard Abul Qasim صلى الله عليه وسلم (Prophet Peace be upon him) who spoke the truth and whose word was verified, say: Mercy is taken away only from him who is miserable.
[Sunan Abu Dawood, Hadith no. 4942, Authentic]