How can the heart, which is fragile, be expected to break a mountain, especially when it has already endured such intense trials of love?

This couplet beautifully captures the overwhelming power of love. The poet asks: What force, even a mighty river, can break a mountain? The answer, according to the poet, is that love itself has tested the limits of human endurance. It suggests that the emotional weight and intensity of love are so profound, they challenge the very laws of nature and physical strength. It's a testament to love's unmatched, devastating power.