peep through

peep through something

to take a quick glance through something, such as a hole, telescope, etc. Sam peeped through the keyhole and saw that the room was dark. Peep through the telescope and have a look at the moon!
See also: peep, through
References in classic literature ?
When he grew tall enough to peep through the keyhole of the great lock of the main door, he had divers times set down his father's dinner, or supper, to get on as it might on the outer side thereof, while he stood taking cold in one eye by dint of peeping at her through that airy perspective.
One of his eyes (perhaps the eye that used to peep through the keyhole) was also weak, and looked larger than the other, as if it couldn't collect itself.