Adam Clarke on 1 Timothy 3:10

Let these - be proved - Let them not be young converts, or persons lately brought to the knowledge of the truth. This is the same in spirit with what is required of the bishops, 1Tim 3:6.

Let no man be put into an office in the Church till he has given full proof of his sincerity and steadiness, by having been for a considerable time a consistent private member of the Church.

Being found blameless - Ανεγκλητοι οντες· Being irreproachable; persons against whom no evil can be proved. The same as in 1Tim 3:2, though a different word is used. See the note on 1Tim 3:2.