Others abide our question. Thou art free.
We ask and ask: Thou smilest and art still,
Out-topping knowledge. For the loftiest hill
That to the stars uncrowns his majesty,
With this opening line Matthew seems to suggest that other people (most likely other writers) are willing to be questioned and that they wish to be valuated by the critics and their readers. They simpy follow the traditions of convential writing. 
 Shakespeare, on the other hand, does no such thing; he’s ‘'free’‘. He doesn’t abide to any questioning, he doesn’t limit his way of thinking, he just follows his heart and is thus free from any criticism and scrutiny. Shakespeare is above other poets and his work will probably never be truly figured out. 

Shakespeare