When the Messenger of Allah ﷺ arrived in Medina, the people had two days on which they used to play during the days of ignorance. He said, "Allah has replaced them for you with two better days, the day of Fitr and the day of Nahr."
حدثنا ابن أبي عدي عن حميد
قدم رسول الله ﷺ المدينة ولهم يومان يلعبون فيهما في الجاهلية فقال إن الله تبارك وتعالى قد أبدلكم بهما خيرا منهما يوم الفطر ويوم النحر
Its isnad is sahih. Ibn Abu Adi is Muhammad bin Ibrahim, mentioned previously. The hadith was narrated by Abu Dawud, 1/295, no. 1134, in the Book of Prayer, chapter on the prayer of the two Eids, and Nasai, 3/179, no. 1556, with similar wording, and Bayhaqi, 3/277.