Having been made perfect (τελειωθεις). First aorist passive participle of τελειοω, the completion of the process of training mentioned by this same verb in Hebrews 2:10 "by means of sufferings" (δια παθηματων) as stated again here in verse Hebrews 5:8.

The author of eternal salvation (αιτιος σωτηριας αιωνιου). Common adjective from αιτια (cause), causing, often in Greek with σωτηριας (Aeschines, Philo), in N.T. only here, Luke 23:4; Luke 23:14; Luke 23:22; Acts 19:40. See same idea in Hebrews 2:10 (αρχηγον). See Isaiah 45:17.