The love between man and woman is like fire. This element can be good and positive — it warms, it lights, it allows cars and other means of transport to move. The world cannot survive without fire. Yet this element can also be extremely destructive: it burns and is the source of danger and heavy damage. What does this depend on? Mastery. A fire that is controlled is positive, while an uncontrolled fire is destructive. The Mitzvah of Taharat HaMishpacha requires self-mastery from both spouses, and it is precisely this control that allows their love to be extremely positive.