Sayyiduna Abdullah Ibn Abbas (Radi Allahu Anhu) has narrated that the Beloved and Blessed Prophet (SallAllahu Alayhi wa Sallam) has said:

"The blessed night of Eid-ul-Fitr is referred to as the ‘Laylatul Jaizah’ (i.e. the Night of Reward). On the morning of Eid, Allah sends His angels to every city where they stand at the end of every street and call out, ‘O Ummah of Muhammad (SallAllahu Alayhi wa Sallam)! Come to the court of Beneficent Allah who grants in abundance and forgives even the most severe sin.’
Allah then says to His servants, ‘O My servants! Ask for whatever you want! I swear by My Honour and Glory! I will grant whatever you ask for about your Hereafter in this gathering (of the Eid Salah) today. And whatever you want regarding the world; I will see your betterment (i.e. I will do what is best for you). I swear by My honour! I will conceal your mistakes as long as you abide by my commandments. I swear by My Honour, I will not humiliate you with the sinners; so return to your homes, forgiven. You have pleased Me and I am pleased with you.’

[At-Targhib Wat-Tarhib, Vol. 2, Page 61, Hadith 1493]