The master knew that if one only realized that one is already enlightened, then one would immediately become enlightened in this life.
In this way, the master saw that Hui-neng’s statement indicated the better understanding of Buddhist enlightenment—immediate enlightenment.
By contrast, Shen-xiu could only hope to achieve gradual enlightenment, because he did not realize that the mind was already pure and ready to attain enlightenment.
Thus, it is said, Hui-neng became the head of the Southern School, which taught immediate enlightenment in this life, while Shen-xiu became a leader of the Northern School, which taught a gradual approach to enlightenment.