حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا حَمَّادٌ، عَنْ حُمَيْدٍ، عَنْ أَنَسٍ، قَالَ قَدِمَ رَسُولُ اللَّهِ صلى الله عليه وسلم الْمَدِينَةَ وَلَهُمْ يَوْمَانِ يَلْعَبُونَ فِيهِمَا فَقَالَ ‏"‏ مَا هَذَانِ الْيَوْمَانِ ‏"‏ ‏.‏ قَالُوا كُنَّا نَلْعَبُ فِيهِمَا فِي الْجَاهِلِيَّةِ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ إِنَّ اللَّهَ قَدْ أَبْدَلَكُمْ بِهِمَا خَيْرًا مِنْهُمَا يَوْمَ الأَضْحَى وَيَوْمَ الْفِطْرِ ‏"‏ ‏.‏

Narrated Anas ibn Malik: When the Messenger of Allah (PBUH) came to Medina, the people had two days on which they engaged in games. He asked: What are these two days (what is the significance)? They said: We used to engage ourselves on them in the pre-Islamic period. The Messenger of Allah (PBUH) said: Allah has substituted for them something better than them, the day of sacrifice and the day of the breaking of the fast. Translation Not Available

Book Ref: Sunan Abi Dawud Book 2 Hadith 1134
Web Ref:  Sunan Abi Dawud Book 3 Hadith 1130