Maria Popova over at Brainpickings has a great post about Medieval scribes' comments in the margins. I love the subversiveness of this hand of God complaining in the corners, the assertion of self.
Here are a few:
Writing is excessive drudgery. It crooks your back, it dims your sight, it twists your stomach and your sides.
As the harbor is welcome to the sailor, so is the last line to the scribe.
This is sad! O little book! A day will come in truth when someone over your page will say, ‘The hand that wrote it is no more.’