The mystical knot, also called a knot of longevity, an endless knot, is a knot of happiness. This symbol is found in different ancient traditions: in Tibetan Buddhism (it is believed that it comes from there), in Islam and in Celtic ornaments. It has no beginning and no end, therefore it is called mystical, infinite, eternal.
It is a traditional symbol of luck in Buddhism, symbolizing the idea of reincarnation and infinity of life. Having a lot of interlacing, it symbolizes the idea of unity of all things and the connection of people, events. In China, it is considered a symbol of longevity, love and harmony.
A mystical node refers to the number of characters that do not "work" by themselves. Whether the knot is small or large, it "works" only when the person pays their attention to it, when the man knows what is represented by the node.