https://books.google.ca/books?id=WWREDwAAQBAJ&pg=PA136&lpg=PA136&dq=%E5%9D%90%E5%BF%98+%E8%80%81%E5%AD%90&source=bl&ots=Elu8CPmyMV&sig=dBvnfdcCJpHHwgiM9Uh9USctWiQ&hl=zh-CN&sa=X&ved=2ahUKEwiy97648bDeAhWId98KHUflDTwQ6AEwBXoECAUQAQ#v=onepage&q&f=false
《庄子·人世间》:若一志;无听之以耳,而听之以心;无听之以心,而听之以气;听止于耳,心止于符。气也者,虚而待物者也,唯道集虚,虚者心斋也。”