What is the creation that Allah Almighty will bring into existence for Paradise after whatever He wills of it remains?

The authenticated Hadith (Hell will continue to have thrown into it [people], and it will say, 'Is there any more?' until the Lord of Glory places His foot therein. Then some parts of it will fold into others, and it will say, 'Enough, enough, by Your Glory and Generosity.' And there will still be a surplus in Paradise until Allah creates a new creation for it, and He will house them in the surplus of Paradise) indicates that Allah Almighty will create a new creation to house them in the surplus of Paradise. The true nature of this creation is among the matters of the unseen, which Allah and His Messenger have not clarified. Knowing about it does not entail any virtue or action, and ignorance of it does not diminish any obligatory or supererogatory act of worship. We have been forbidden from over-exerting ourselves in asking about what has not been made known, as Allah Almighty says: (Say, 'I ask no reward of you for it, nor am I one of the pretentious') [Saad/86]. And in the Hadith: "We have been forbidden from over-exertion." And in the Hadith: (Indeed, Allah has enjoined duties, so do not neglect them. He has set limits, so do not transgress them. He has forbidden things, so do not violate them. And He has remained silent about things, as a mercy to you, not out of forgetfulness, so do not inquire into them). Therefore, we should not burden ourselves with searching into what is hidden from us, and we should focus on what Allah has legislated for us.