This metaphor explains that marriage requires constant care and effort to remain vibrant and strong. If one neglects their marriage or does not make an effort to maintain love and the relationship, it eventually dies out or becomes stagnant, like fat that solidifies when moved away from the fire. In other words, this expression means that for a romantic relationship to thrive, one must continuously nurture and work on it. An equivalent proverb would be: ‘Marriage is a garden that needs to be watered every day so that it doesn’t dry up.’