What is the meaning of the noble Hadith: "Whoever does not forgive will not be forgiven," and does it mean that if one does not forgive those who wronged him, Allah will not forgive him?

The aforementioned hadith (definition), "He who does not show mercy will not be shown mercy, and he who does not forgive will not be forgiven," was graded hasan (definition) by Al-Albani. Muslim narrated it with the wording: "He who does not show mercy to people, Allah will not show him mercy." These narrations indicate that recompense is of the same nature as the deed, and that whoever forgives people and overlooks their mistakes will be forgiven and shown mercy by Allah. This is further clarified by the Hadith Qudsi: "There was a man who used to lend money to people... then he met Allah and Allah overlooked his sins." The meaning of the hadith is not that if a Muslim does not relinquish his right, Allah will not forgive him, for Allah Almighty says: ﴿And the recompense of an evil deed is an evil deed like it. But whoever pardons and makes reconciliation – his reward is due from Allah. Indeed, He does not like wrongdoers.﴾ [Ash-Shura: 40]. So, the oppressed has the right to take his due, but forgiveness is more meritorious and closer to piety.