1. Then: —This sonnet continues the thought of the previous one, which ended with the statement that "flowers distill'd, though they with winter meet, / Leese but their show, their substance still lives sweet."   ragged: rough.

3. vial: metaphorically, a woman.  treasure: enrich.

5. use: lending money at interest.  usury: lending money at a predatory rate of interest.

6. happies: makes happy. pay the willing loan: willingly repay the loan. —Metaphorically, the loan is made by the fair young man to a woman. He lends her his essence, and she repays him with a child.

8. be it: if it were.  ten for one: i.e., 10% interest. —Ten percent was the highest legal rate of interest, but the poet here speaks of a high rate of interest as a good thing, since the repayment is to be made in children.

10. refigur'd thee: i.e., looked like you.

13. self-will'd: 1) obstinate; 2) leaving your inheritance only to yourself.