《庄子·内篇·德充符》
要使心灵平和安适，通畅而不失怡悦，要使心境日夜不间断地跟随万物融会在春天般的生气里，这样便会接触外物而萌生顺应四时的感情。
使之和豫，通而不失于兑。使日夜无隙，而与物为春，是接而生时于心者也。
Thus he is able quietly to preserve his heart's peace, to be in tune with all things, and to make his spirit one with that of Heaven and Earth. By this means he comes into contact with external things and is responsive to the seasonal changes, and is like one who, with bent head, is receptive to the winds of spring.