Hyakujo, the Chinese Zen master, used to labor with his pupils even at the age of eighty, trimming the gardens, cleaning the grounds, and pruning the trees.
The pupils felt sorry to see the old teacher working so hard, but they knew he would not listen to their advice to stop, so they hid away his tools.
That day the master did not eat. The next day he did not eat, nor the next. “He may be angry because we have hidden his tools,” the pupils surmised. “We had better put them back.”
The day they did, the teacher worked and ate the same as before. In the evening he instructed them: “No work, no food.”