From "The Tuan says: Treading: softness treads on firmness" to "it does not bite the man; prosperity." The Zhengyi commentary says: "Treading: softness treads on firmness" means the sense of the hexagram Treading is softness treading on firmness.
Six in the Third Place, a yin line, is above Nine in the Second Place, a yang line; hence "softness treads on firmness." "Treading" means stepping upon. This explains the name and meaning of Treading.
"Joyous and responding to The Creative, therefore treading on the tiger's tail, it does not bite the man; prosperity": this explains the meaning of "not biting the man; prosperity."
Six in the Third Place belongs to the body of Dui, and Dui represents harmonious joy, responding to Nine at the Top, which belongs to The Creative.
Dui is naturally harmonious and joyous, responding to the firmness of The Creative; responding to firmness with joy, it suffers no harm. Therefore, treading on a tiger's tail, it does not bite or harm the person, and attains prosperity.
If one practiced harmonious joy toward yin softness, that would be the path of flattering depravity; because it responds to firmness with joy, it attains good fortune.
The Zhengyi commentary says: "Firm, central, and correct, he treads the imperial throne": this refers to Nine in the Fifth Place.
Residing in the center with firmness, attaining his Correct Position, and dwelling in the honor of Nine in the Fifth Place—this is "firm, central, and correct, he treads the imperial throne."
"Without distress, his brilliance shines": being able to occupy the imperial throne with firm centrality without suffering affliction or disease is due to the brightness of his virtue.
This single sentence praises the beauty of the hexagram's moral cultivation, without interpreting a specific phrase from the classic.