Hold the reins of control over your heart right from the beginning; O sorrowful lover, of what use will it be if you try to rein it in later?

The poet beautifully compares the heart to an untamed horse whose reins of control must be gathered tightly right at the beginning. Once the storm of love sweeps you away and the heart bolts uncontrollably, trying to pull back on the bridle later will be entirely futile. It is the gentle, knowing counsel of a friend urging a vulnerable lover to guard their emotions before despair makes any restraint impossible.