za.chach denotes being kept from detaching, describing the breastpiece secured to the ephod.

The attested use describes the breastpiece being prevented from detaching from the ephod: both clauses place the Niphal imperfect form in the instruction or fulfillment that secures the breastpiece by a blue cord.

1. Kept from detaching from the ephod · dominant

   In Exodus 28:28, the Niphal imperfect occurs in the clause following the binding of the breastpiece to the ephod; the APB renders that result as “the breastpiece shall not be removed from the ephod.” Exodus 39:21 repeats the same form and arrangement in the completed action, where the APB renders “the breastpiece would not be removed from the ephod.”

   Exodus 28:28Exodus 39:21

In the Anselm Project Bible: Across both verses, the APB presents the clause as the breastpiece not being “removed from the ephod.” This reflects the clause's result rather than isolating a precise English equivalent.