The couplet in this sonnet is:
For thy sweet love remembered such wealth brings,;
That then I scorn to change my state with kings.
A couplet refers to two successive rhyming lines that have the same meter. Moreover, the couplet forms a complete thought. In most sonnets, particularly Shakespearean ones, the couplet is placed at the end of the poem. The purpose of these lines is to emphasize the theme of the poem. Therefore, they give the feeling of conclusion. In this sonnet, these lines are effective in fulfilling this purpose, as they reemphasize the idea that the love of the woman is more important than all the riches and all the status in the world.