The third  sonnet by Shakespeare belongs to marriage sonnet.

Now I am going to make denotative analysis.

Look in your mirror and tell the face you see
That now is the time it should form another
If you do not renew yourself,
You rob the world, and prevent some woman from becoming a mother.
For where is the woman whose unploughed womb
Would frown upon the way you plough your field?
Or who is he so foolish to love himself so much but let
Himself perish?
You are the mirror of your mother, and she is the mirror of you
And in you she recalls the lovely April of her youth:
So too will you see when you are old,
Free of wrinkles, these are your best years.
But if you live your life avoiding being remembered.
You will die childless, and your image will die with you.