The third sonnet is written by Shakespeare, and it belongs to his "Marriage sonnets".

It is a Shakespearian sonnet, and so it is arranged into three quatrains and a final rhyming couplet.

In the first quatrain the narrator invites a young man to have a child and to bless a mother, in order to reproduce his beauty.

In the second one the speaking voice justifies the piece of advice given in the previous four lines. He tells him that he can have whatever woman he wants not to stop posterity.

In the last quatrain the narrator explains the link between parents and sons: parents can see themselves (at their "golden time") in them son's aspect.

The function of the final rhyming couplet is to underline the piece of advice given in the first quatrain, giving the interlocutor more argumentations.