Fundamentals of the Wudang Sword Method - trans by Scott Rodell

心空歌
歌曰。手心空。使劍活。足心空。行步捷。頂心空。身眼一。

Xīn kōng Gē
Gē yuē. Shǒuxīn kōng. Shǐ jiàn huó. Zú xīn kōng. Xíng bù jié. Dǐng xīn kōng. Shēn yǎn yī.

Song of Empty Mind
The song says
With palm empty, the sword is lively.
With the center of the foot empty, the footwork is nimble.
With the topknot empty, the entire body is one.

Commentary and Notes: This short “song” describes the body once one is free from premeditated action. Simply put, when one is not predisposed to use a certain cut, one is free to cut in any manner. Likewise, when one is not planning on stepping here or there, one will freely move anywhere. When one is not thinking ahead without attachment to a certain action of set of rules, but “empty” in the moment, one is free from dogmatic actions, and can clearly see without the filters of habit and prejudice moving with true freedom.
The topknot refers to a daoist hairstyle where long hair is wound up into a knot that sits atop the apex of the head, held in place by a peg. “Keeping the topknot empty” means not hanging the head, inclining the body forward, nor titling the head back, so that it is pulling the body backward off balance.

Quoted from-
Fundamentals of the Wudang Sword Method - Selected Translations with Commentary from a Manual of Chinese Swordsmanship

This and Rodell Laoshi's other books can be found at-
https://www.amazon.com/Scott-M.-Rodell/e/B001K8ZF56