《庄子·杂篇·徐无鬼》
舜治理这块荒漠的土地，年龄大了，耳目衰退了，而无法回家休息，这就叫做形劳自苦的人。
舜举乎童土之地，年齿长矣，聪明衰矣，而不得休归，所谓卷娄者也。
Shun developed that uncivilized area, got old, and his hearing and sight were diminished but he couldn't go home and rest, that's someone who toils.