faithful in all his house - that is in all God’s house (Heb 3:4).
servant - not here the Greek for “slave,” but “a ministering attendant”; marking the high office of Moses towards God, though inferior to Christ, a kind of steward.
for a testimony of, etc. - in order that he might in his typical institutions give “testimony” to Israel “of the things” of the Gospel “which were to be spoken afterwards” by Christ (Heb 8:5; Heb 9:8, Heb 9:23; Heb 10:1).