In the sonnet III Shakespeare puts face to face 2 men: the first one , the interlocutor (Shakespeare himself), tells to the other to see himself in the glass and to tell him about what kind of man he sees. After that the interlocutor tells him that the time to have a child has come, that his beauty must be transmitted. the speaking voice uses a series of arguments to support his advice, his will: he says that no woman can refuse to give him a child thanks to his extraordinary beauty, that when he'll be old he can see his youth through looking his son, comparing this probably situation to the one in which his mother"returns" young thanks to the simple looking at him. Thanks to the speaking voice's words and the emphasys that he transmits giving him this advice the reader understands that he admires this beauty, this young man, and does not want to see it waste, but time passes soShakespeare hopes that the young man takes a quick decision.