Answer:
When about to divide his kingdom among his three daughters, he asks them how much they love him, and he will give each of them part of the kingdom based on their respective answers. His eldest daughter, Goneril, proclaims her love for him in a very exaggerated tone, saying "A love that makes breath poor and speech unable; / Beyond all manner of so much I love you." His middle daughter, Regan, spills out an equally melodramatic response in saying her love for him. His youngest and favorite daughter, Cordelia, merely says "Nothing, my lord", justifying that "I cannot heave my heart into my mouth", or what she feels she cannot form into words.