Sayyiduna Abbas bin Mirdas (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) made abundant supplication for forgiveness and mercy for his Ummah on the evening of Arafah. So Allah Almighty accepted your (peace and blessings be upon him) supplication and said: Surely, indeed I have done so and have forgiven your Ummah, except those who wrong each other. The Prophet (peace and blessings be upon him) said: O my Lord! You are capable of forgiving the oppressor and granting the oppressed a better reward and recompense than the wrong done to him. That evening, this is what happened, meaning on the evening of Arafah this supplication of the Prophet (peace and blessings be upon him) was not accepted, as is mentioned in some narrations. When the next day came, the Prophet (peace and blessings be upon him) began to supplicate for his Ummah on the morning of Muzdalifah. Soon, the Prophet (peace and blessings be upon him) began to smile. A companion said: O Messenger of Allah! May my parents be sacrificed for you, you have smiled at such a moment in which it is not your habit to smile, so what has made you smile? May Allah always keep your blessed teeth smiling. The Prophet (peace and blessings be upon him) said: I smiled because of Allah's enemy, Iblis. When he learned that Allah Almighty had accepted my supplication for my Ummah and had also forgiven the oppressor, he cried out for destruction and began to throw dust on his head. So I smiled upon seeing his distress and grief.