«My tongue-tied Muse in manners holds her still,
While comments of your praise, richly compiled».
The poet likens himself to an “unlettered clerk” and finds his Muse “tongue-tied” — the identical phrase the poet used in Sonnet 80 to characterize himself.
My tongue-tied Muse in manners holds her still,
His rival seems a more gifted poet and a better-esteemed person, but in supposing himself and his work to possess little virtue, the poet maintains his usual ironic tone. The reader cannot, therefore, take his self-deprecating tone seriously, not so long as he continues to write the poetry that he says he despises: “I think good thoughts, whilst other write good words.” Although he acknowledges that his own thoughts are expressed with greater refinement and grace by other poets, he maintains that his devotion to the young man has greater merit.
English audio from YouTube Channel Socratica
Summary from Cliffsnotes.com