The Arhat Fist that was agreed, how did it become the palm of the Tathagata?

After waking up, Xiao Xun traveled to the world of martial arts and became a little monk in Shaolin Temple.
Due to his poor talent, he can only practice superficial skills such as Arhat Boxing and Golden Bell Mask.
After ten years of cultivation, I thought I would accomplish nothing.
Who knew, when he left the temple, he directly became a new myth of martial arts.
Xiao Xun: "It's strange, why is this river and lake so untroubled?"
......