You are reading a tafsir for the group of verses 56:21 to 56:26
وَلَحْمِ طَيْرٍ مِّمَّا يَشْتَهُونَ (and the meat of birds that they desire....56:21]. It is recorded in a Prophetic Tradition that the inmates of Paradise will get meat of whatever birds they desire, as and when they desire it.