This song is a direct plea to a suffering heart, telling it to be strong and not give in to sadness. El Fantasma sings directly to his heart, saying, "Corazón, no es hora de llorar" [Heart, it's not time to cry] and "Aguanta tu penar" [Endure your sorrow]. He's really feeling his heart's pain as his own, admitting, "Tu dolor también es mi dolor" [Your pain is also my pain].
It's a really relatable feeling when you're trying to be tough, but your emotions are just overwhelming you. He even asks, "Corazón, por qué te empeñas en hacerme sufrir" [Heart, why do you insist on making me suffer?], which is such a blunt and honest question. It's like he's having a conversation with his own feelings, urging them to "Mantente en calma" [Stay calm] even though it's clearly a struggle.