A.T. Robertson Commentary 1 Timothy 3:10

"And let these also first be proved; then let them serve as deacons, if they be blameless." — 1 Timothy 3:10 (ASV)

First be proved (δοκιμαζεσθωσαν πρωτον). Present passive imperative third plural of δοκιμαζω, old and common verb, to test as metals, etc. (1 Thessalonians 2:4, and often in Paul). How the proposed deacons are to be "first" tested before approved Paul does not say. See Php 1:10 for the two senses (test, approve) of the word.

Let them serve as deacons (διακονειτωσαν). Present active imperative of διακονεω (same root as διακονος), common verb, to minister, here "to serve as deacons." Cf. διακονειν in Ac 6:2. See also verse 13.

If they be blameless (ανεγκλητο οντες). "Being blameless" (conditional participle, οντες). See 1 Corinthians 1:8; Colossians 1:22 for ανεγκλητος.