When I first read that phrase from yuuji,my mind instantly clicked it to yuuji playing on sukuna's arrogance regarding humanity,but it's more reflective of the lotus sutra's teachings,which discusses the interconnectedness of all beings and the idea of enlightenment through understanding this connection,it's yuuji accepting his cursed side or maybe making sukuna accept his human side,yuuji should or already has attained buddhahood (become a true jujustu sorcerer)

I think a few elements of the seven parables can match with the jjk lore,if we read between the lines,it's very indistinct, so far I belive it could be:-

1) The Parable of the Father and his Lost Son, (Chapter 4 - Faith and understanding)

A son, estranged from his wealthy father, is gradually brought back into the family.

It could be linked to Megumi and toji,would explain toji's return during Shibuya,also to kenjaku and yuuji, kenjaku's main purpose of birthing sukuna's vessle but yuuji rejecting that fate in a way,instead coming to an understanding of his place in the world of jujutsu sorcery for the better.

2) The parable of the jewel in the robe,(chapter 8 - Prophecy of Buddhahood)

A man discovers a gem hidden by his friend inside his garment, symbolizing the inherent Buddha-nature within all beings.

This could generally conclude to the jjk characters discovering their true potential or hidden powers,such as Megumi's gradual realization of his own strength,crafting his domain and Yuuji's discovery of his cursed technique.

I read the seven parables a long time ago,so I might have not made the most accurate connections here- sorwwy😭,yes the stories are really interesting and provide great insights,I'll be eagerly waiting to hear your opinions on this!🪷🪷