All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
The first food to be eaten by the people of Paradise is the rim of a whale’s liver. On the authority of Anas ibn Maalik ‘Abdullaah ibn Salaam came to the Prophet, sallallaahu ‘alayhi wa sallam, when he knew of his coming to Madeenah and asked him about three things that could only be known to a prophet, one of which was what would be the first food eaten by the people of Paradise. The Prophet, sallallaahu ‘alayhi wa sallam, answered that it would be the edge of a whale’s liver. Having heard that, ‘Abdullaah ibn Salaam embraced Islam. [Al-Bukhari]
Allaah Knows best.