The scene above, Gojo comforted Yuji as he knew that he was terrifid seeing jogo raw power. Then after he defeated him he said this statement. In summary, Gojo saying that Jogo was weak was a ploy for Jogo to show his true power and that he said that Yuji and the others must be powerful enough to beat him.

Jogo ( o 0X00F tZ 0T , J
Mgo^?) is a major antagonist in the Jujutsu Kaisen series. He was an unregistered special grade cursed spirit aligned with Mahito, Hanami, and Dagon.