That > [So that]
8 And with the wonder of her beams bright,
her beams > (Cynthia is an aspect of Diana, goddess of the moon) bright > bright; beautiful
9 My senses lulled are in slumber of delight.
300.5
But let that same delitious Poet lend
2 A little leaue vnto a rusticke Muse
To sing his mistresse prayse, and let him mend,
4 If ought amis her liking may abuse:
Ne let his fairest Cynthia refuse,
6 In mirrours more then one her selfe to see,
But either Gloriana let her chuse,
8 Or in Belph{oe}be fashioned to bee:
In th'one her rule, in th'other her rare chastitee.
1 But let that same delicious poet lend 2 A little leave to a rustic Muse
Muse > (Here the word is used metonymically to mean "poet")
3 To sing his mistress' praise, and let him mend,
mend > [mend my verses]