Only here in Hebrews, and besides, only Luk 12:58; Act 19:12. Tolerably often in lxx. Very common in Class. Used here absolutely, not with δουλείας bondage, reading deliver from bondage.
Subject to bondage (ἔνοχοι δουλείας)
Ἔνοχοι from ἐν in and ἔχειν to hold. Lit. holden of bondage. See on Jam 2:10. Comp. the verb ἐσέξειν, Mar 6:19 (note), and Gal 5:1. Δουλεία bondage only in Hebrews and Paul.