In the verse, “Take ye therefore good heed unto yourselves,” the care refers primarily to the spiritual soul. However, one cares for the corporeal soul even without commandments from the Torah.
This is because in the corporeal soul a person feels that he is harmed. If you put your hand in the fire, of course, you will immediately take care of yourself. Likewise, if you feel that moving your hand from the chair to the table, you will feel greater pleasure and profit, then, of course, you will do that; you have the fuel to make this movement...