“This is the path of Torah: Lead a sorrowful life.”
Because he works for the sake of the Creator, the body has no pleasure because it is not receiving anything. But when accustoming the body to work in bestowal, against its will, we are rewarded with “Then shall you delight in the Lord.” That is, when we work for the sake of the Creator, we receive pleasure, and this is called “Her ways are ways of pleasantness.”