The speaker of marriage sonnet 13 is the same speaker of the marriage sonnets 1-12, of course, and the reader will not fail to perceive correctly the same theme: encouraging, cajoling, and wheedling the young man to marry and produce pleasing offspring, particularly male offspring.
In the first quatrain, the speaker seems to be speaking nonsense as he cajoles the young man, saying if only you were yourself, but, dear one, you are “No longer yours, than you your self here live.” Of course, the speaker is asserting that a human being is not merely given a life for himself alone, while he also coyly reminds the young man of his future non-existence. He says, “Against the coming end you should prepare.” Because the future will soon be here and without you, you should father a child who will resemble you: “your sweet semblance to some other give.”
If the young man’s beauty, which is temporary, should be passed on to another, then the young man will have a certain claim on immortality in his “sweet issue” which will reflect the same sweet qualities as the father. The speaker always finds ways to compliment the young man on his good looks and pleasing qualities. And the speaker is always despairing that the lad is going to let those fair qualities die with himself, instead of passing them on to his heirs.
In the third quatrain, the speaker compares the young man’s physical body to a house, when he poses the rhetorical question: “Who lets so fair a house fall to decay / Which husbandry in honour might uphold / Against the stormy gusts of winter’s day / And barren rage of death’s eternal cold?” He implies that no one would do such a thing, when a little moral forethought would protect the fair house against the ravages of winter weather and bitter cold that decay of the body naturally brings about.
The couplet is blunt, and the speaker even answers the rhetorical question that he knows needs no answer: “O! none but unthrifts. Dear my love, you know / You had a father: let your son say so.” But his last remark is even more blunt and literal as he addresses the lad. You know the sound economy of fathering offspring, because you yourself had a father, so let your son say the same thing. Get busy and marry and produce sons!
Other articles on Shakespeare: Who is Shakespeare?
Sonnet Commentaries: Sonnet 1, Sonnet 2, Sonnet 3, Sonnet 4, Sonnet 5, Sonnet 6, Sonnet 7, Sonnet 8, Sonnet 9, Sonnet 10, Sonnet 11, Sonnet 12, Sonnet 18, Sonnet 19, Sonnet 116, Sonnet 126, Sonnet 130