It was narrated from Bishr bin Suhaim that:

The Prophet ﷺ commanded him to call out on the days of At-Tashriq that no one would enter Paradise except a believer, and that these were the days of eating and drinking.

أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا حَمَّادٌ، عَنْ عَمْرٍو، عَنْ نَافِعِ بْنِ جُبَيْرِ بْنِ مُطْعِمٍ، عَنْ بِشْرِ بْنِ سُحَيْمٍ، أَنَّ النَّبِيَّ ﷺ أَمَرَهُ أَنْ يُنَادِيَ أَيَّامَ التَّشْرِيقِ " أَنَّهُ لاَ يَدْخُلُ الْجَنَّةَ إِلاَّ مُؤْمِنٌ وَهِيَ أَيَّامُ أَكْلٍ وَشُرْبٍ " .