What does Islam say about forgiving others?

"Al-Fudayl also said, "Seeking forgiveness without giving up the sin is the repentance of liars. Rabiah al-Adawiya remarked, "Our seeking forgiveness needs much seeking forgiveness." Some wise people observed, “Whoever seeks forgiveness without regret is mocking Allah, the Exalted, while he does not realize it. A Bedouin was heard clinging to the curtains of the Kaaba, saying, "O Allah, truly my seeking forgiveness while persisting is a betrayal, and abandoning seeking Your forgiveness while knowing Your vast pardon is weakness."

"He said: "Allah the Exalted says: 'O My servants, you all sin by day and by night, and I forgive all sins, so ask Me for forgiveness and I will forgive you. And whoever knows that I have the power to forgive him, I forgive him, and it does not bother Me.'" The Prophet, peace be upon him, said: "Whoever says, 'Glory be to You, I have wronged myself and committed an evil deed, so forgive me, for no one forgives sins except You,' his sins will be forgiven, even if they were numerous as the froth of the sea.""

"When asked what it was, he replied, "Seeking forgiveness. He used to say, "Allah does not inspire a servant to seek forgiveness unless He intends to forgive him." Al-Fudayl explained that when a servant says, "I seek forgiveness from Allah," it means "Pardon me. Some scholars noted, "The servant is between a sin and a blessing, and nothing will rectify them except praise and seeking forgiveness."

"Seeking forgiveness using the names found in the Qur'an is preferable, such as saying, "I seek forgiveness from God, He is indeed oft-forgiving. I seek forgiveness from God, He is indeed oft-returning in mercy. O Lord, forgive and have mercy, for You are the best of the merciful ones. So forgive us and have mercy upon us, for You are the best of the merciful ones. So forgive us and have mercy upon us, for You are the best of forgivers.""

"Indeed, we will thank for blessings even if they are denied, and we have reserves after this day. So clothe with pardon those you once nursed from your mothers, for pardon is well known. Indeed, we hope for pardon from you that you will bestow upon this creation when you forgive and take vengeance. So forgive, may Allah pardon what you fear, on the day of resurrection when victory is granted to you."

""The one who seeks forgiveness from a sin while persisting in it is like one who mocks the signs of Allah. Some would say, "I seek Allah's forgiveness from saying 'I seek Allah's forgiveness. It is said, "Seeking forgiveness with the tongue is the repentance of liars. Rabi'a al-Adawiya said, "Our seeking forgiveness itself needs a great deal of seeking forgiveness."

"Rabi'a al-Adawiya said, "Our seeking forgiveness itself needs a great deal of seeking forgiveness. Know that there are reports on the virtue of seeking forgiveness beyond count, mentioned in the Book of Supplications and Invocations, to the extent that Allah coupled seeking forgiveness with the presence of the Messenger, peace be upon him, saying, "And Allah would not punish them while you are among them; and Allah would not punish them while they seek forgiveness."

"The effects of His displeasure pass away swiftly; He, glorified be He, may efface them by pardon and overlooking, and they pass away through repentance, through seeking forgiveness, through righteous deeds, through afflictions that expiate, through intercession, and through good deeds that drive away evil ones. Were a servant's sins to reach the clouds of heaven, and then he sought His forgiveness, He would forgive him; and were he to meet Him with sins nearly filling the earth, and then meet Him associating nothing with Him, He would come to him with forgiveness nearly as vast."

""A servant committed a sin and said, 'O Lord, I have sinned, so forgive me. In another narration, "A servant committed a sin and said," and continued. The hadith, "Even if a servant's sins reach the clouds of the sky, if he seeks My forgiveness, I forgive him," was reported by al-Tirmidhi from the narration of Anas. "O son of Adam, if your sins reached the clouds of the sky, and then you asked for My forgiveness, I would forgive you," and it was considered good by him."

"The third point is the feeling of self-sufficiency from the forgiveness and pardon of اللّٰه, due to their belief in deserving forgiveness and reward through their good deeds and acts of obedience. They think that salvation and reward are achieved through their acts of obedience, and they consider their abundance of good deeds as a sign of independence from اللّٰه's forgiveness and pardon. This is the essence of arrogance and presumption against اللّٰه."