What is the ruling on saying "I am entering Paradise" without the qualifier "God willing," and is repentance obligatory for the one who says it?

If a person says that he is among the people of Paradise out of optimism, without intending to praise himself or bear witness for himself, there is no harm in that. However, if he intends to praise himself, boast about his deeds, or be certain of Paradise, then this is forbidden in Sharia, due to Allah's saying: "So do not praise yourselves; He is most knowing of who is righteous." (Quran 53:32). And whoever falls into that should repent to Allah with sincere repentance and increase in good deeds and ask Allah for steadfastness and a good end.