596 Your gracious sovereign's praises to compile. 597 And her imperial majesty to frame, 598 In lofty numbers and heroic style.

numbers > metrical lines; hence: verses style > style; literary composition

599 But sith you may not so, give leave a while

sith > since may not so > [are prevented from doing so]

600 To baser wit his power therein to spend,

baser > [a] baser wit > mind

601 Whose gross faults your dainty pen may file,

dainty > {Of delicate taste; hence: discerning} file > polish

602 And unadvised oversights amend. 603 But evermore vouchsafe it to maintain

maintain > defend