Will no one rid me of this troublesome priest?
According to the Gemeniz (reddit sourced) the line from history is "Will none of these lazy insignificant persons... deliver me from this turbulent priest?" although this was recorded hundreds of years after the fact of its utterance. The essence being that Henry being used to throwing his weight around was truly surprised that his complaint was regarded as an order.
The screenplay of Becket treats this gingerly, O'Toole gives King Henry both grief at the loss of his friend, and elation that his figurehead enjoys new status as Becket is sainted.