Not wanting to believe it and still remembering quite clearly how that same eye was also the last eye she saw on the day of her death.
"As good as you deserve," said Belhart very calmly
And Monna simply cannot measure the extent to which that kindness will be properly given to her. Not mentioning the size and also the limits made Monna guess a little, could Belhart say that to test her?
Where Belhart actually wanted to say that:
If Cattarina were obedient and respectful to him, then would he repay her a natural kindness? Not privileged. Just do to the extent where Belhart's mood will make way for him.
Then, if Cattarina was disobedient and disrespectful and lied to him. Could it be that Belhart would immediately revoke the goodness and turn it into good in a bad sense to make Cattarina realize that she couldn't do anything without him?