Looke in thy glasse and tell the face thou viewest,
Now is the time that face should forme an other,
Whose fresh repaire if now thou not renewest,
Thou doo'st beguile the world, unblesse some mother.
For where is she so faire whose un-eard wombe
Disdaines the tillage of thy husbandry?
Or who is he so fond will be the tombe
Of his selfe love to stop posterity?
Thou are thy mothers glasse and she in thee
Calls back the lovely Aprill of her prime,
So thou through windowes of thine age shalt see,
Dispight of wrinkles this thy goulden time.
But if thou live remembred not to be,
Die single and thine Image dies with thee.
In the first quatrain, the poet warns the young man that he should set about creating another face like his own, otherwise he wll be cheating the world, and depriving some potential mother of the joy of bearing his child.
The second quatrain asks two questions: what woman would not gladly bear the young man's child, and who would be so stupid as to close himself up in self-love and not produce offspring.
The third quatrain points out that the young man is the image of his own mother, and, should he similarly produce his own offspring, he will be able to see his own 'golden time' in them. The portraits of Henry and of his mother certainly confirm what is said here.
The final couplet makes the observation that should he not marry and procreate, then his image will die with him.