"Losing for Tao" comes from the Tao Te Ching, and the whole sentence is "losing for Tao", which means that people who study are getting lewd every day; Those who seek Tao, their pornographic decorations are decreasing day by day. "Doing harm to others for the sake of Taoism" can be understood as a manifestation of self-discipline, which conveys the idea that people who pursue Taoism should restrain themselves and practice by reducing their lust and material pursuit.
Self-discipline is the ability to control and manage one's own behaviors and desires. "Doing harm for the Tao" emphasizes the importance of reducing lust, because lust and material pursuit often become the root of people's loss and persistence. People can often achieve freedom and peace of mind by self-discipline and getting rid of the bondage of desire.