Seek unto - Consult in your national difficulties.
them ... familiar spirits - necromancers, spirit charmers. So Saul, when he had forsaken God (1Sa 28:7, etc.), consulted the witch of En-dor in his difficulties. These follow in the wake of idolatry, which prevailed under Ahaz (2Ki 16:3, 2Ki 16:4, 2Ki 16:10). He copied the soothsaying as he did the idolatrous “altar” of Damascus (compare Lev 20:6, which forbids it, Isa 19:3).
wizards - men claiming supernatural knowledge; from the old English, “to wit,” that is, know.
peep - rather “chirp faintly,” as young birds do; this sound was generally ascribed to departed spirits; by ventriloquism the soothsayers caused a low sound to proceed as from a grave, or dead person. Hence the Septuagint renders the Hebrew for “necromancers” here “ventriloquists” (compare Isa 29:4).
mutter - moan.
should not, etc. - The answer which Isaiah recommends to be given to those advising to have recourse to necromancers.
for the living, etc. - “should one, for the safety of the living, seek unto (consult) the dead?” [Gesenius]. Lowth renders it, “In place of (consulting) the living, should one consult the dead?”