"Xingxin Pavilion" by Chen Bin of the Song Dynasty: "The king of heaven is calm at first, and all the surroundings are absolutely dim."
"Reading the Taoist Canon" by Su Shi of the Song Dynasty: "When a perfect person realizes a word, the Taoist collection will be empty from the middle."
"Xunzi: Theory of Heaven": "The heart is empty in the middle to regulate the five senses. This is called the Lord of Heaven."
Intention: "Reading the Taoist Canon" by Su Shi of the Song Dynasty: "The perfect person realizes a word, and the Taoist collection is empty from the middle."