roost, hen coop, spiral
塒 centers on a place where birds settle for rest: a roost or hen coop. The spiral sense likely comes from the shape of a coiled roosting spot or nest.
塒 combines 土 (earth) with 時, which likely contributes the sound. The character is associated with a roosting place on the ground or an earthen coop.
The earth radical 土 beside 時 (time) suggests a place on the ground where birds spend their resting time: a roost or coop.
For シ, imagine a hen sitting quietly on her roost, making a soft 'she' sound: she -> シ, and she is resting in the coop.