The devotion of faith, which would manifest itself in obedience to the commandment to keep God's Sabbaths and to reverence His sanctuary Leviticus 19:30, is the true preservative against the superstition which is forbidden in this verse. The people whose God was Yahweh were not to indulge those wayward feelings of their human nature which are gratified in magical arts and pretensions. Compare Isaiah 8:19.
Familiar spirits - literally, "bottles". This application of the word is supposed to have been suggested by the tricks of ventriloquists, within whose bodies (as vessels or bottles) it was fancied that spirits used to speak. In other cases, the word is used for the familiar spirit which a man pretended to employ in order to consult, or to raise, the spirits of the dead. See 1-Samuel 28:7-8.
Wizard - A word equivalent to "a knowing man", or, "a cunning man".

Regard not them that have familiar spirits - The Hebrew word אבות oboth probably signifies a kind of engastromuthoi or ventriloquists, or such as the Pythoness mentioned Acts 16:16, Acts 16:18; persons who, while under the influence of their demon, became greatly inflated, as the Hebrew word implies, and gave answers in a sort of frenzy. See a case of this kind in Virgil, Aeneid, l. vi., ver. 46, etc.: -
" - Deus ecce, Deus! cui talla fanti
Ante fores, subito non vultus, non color unus,
Non comptae mansere comae; sed pectus anhelum,
Et rabie fera corda tument; majorque videri,
Nec mortale sonans, afflata est numine quando
James propiore Dei."
- Invoke the skies, I feel the god, the rushing god, she cries.
While yet she spoke, enlarged her features grew,
Her color changed, her locks dishevelled flew.
The heavenly tumult reigns in every part,
Pants in her breast, and swells her rising heart:
Still swelling to the sight, the priestess glowed,
And heaved impatient of the incumbent god.
Pitt.
Neither seek after wizards - ידענים yiddeonim, the wise or knowing ones, from ידע yada, to know or understand; called wizard in Scotland, wise or cunning man in England; and hence also the wise woman, the white witch. Not only all real dealers with familiar spirits, or necromantic or magical superstitions, are here forbidden, but also all pretenders to the knowledge of futurity, fortune-tellers, astrologers, etc., etc. To attempt to know what God has not thought proper to reveal, is a sin against his wisdom, providence, and goodness. In mercy, great mercy, God has hidden the knowledge of futurity from man, and given him hope - the expectation of future good, in its place. See Clarke's note on Exodus 22:18.

Regard not them that have familiar spirits,.... The word used signifies "bottles", and that sort of diviners here intended go by this name, either because what they sat on when they divined was in the form of a bottle, or they divined by one, or they were swelled and inflated as bottles when they delivered out their answers, or spoke as out of a bottle or hollow place; hence they are called masters or mistresses of the bottle: they seem to be the same with the ventriloquists, and so the Septuagint version here calls them; such whose voice seemed to come out of their bellies, and even the lower parts of them; and such was the Pythian prophetess at Delphos, and very probably the maid in the times of the apostles, who had a spirit of divination, or of Python, Acts 16:16; and so the words may be rendered here, "look not to the Python" (n), or those who have the spirit of Python; so Jarchi from the Misnah (o) interprets the word here used, "Baal Ob" or the master of the bottle, this is Python, one that speaks from under his arm holes:
neither seek after wizards; such as pretend to a great deal of knowledge, as the word signifies; such as are called cunning men, who pretend to know where lost or stolen goods are, and to tell people their fortunes, and what will befall them hereafter:
to be defiled by them; for by seeking to them, and believing what is said by them, and trusting thereunto, and expecting events answerable to their predictions, they would be guilty of a gross sin, and so bring pollution and guilt on them; according to the Jewish canons (p), such sort of persons as are cautioned against were to be stoned, and they that consulted them to be reproved:
I am the Lord your God; who only is to be regarded and sought unto for advice and assistance; see Isaiah 8:19.
(n) "ne respiciatis ad Pythonas", Montanus; so Junius & Tremellius, Piscator. (o) Misn. Sanhedrin, c. 7. sect. 7. (p) lbid.

Regard not them that have familiar spirits--The Hebrew word, rendered "familiar spirit," signifies the belly, and sometimes a leathern bottle, from its similarity to the belly. It was applied in the sense of this passage to ventriloquists, who pretended to have communication with the invisible world. The Hebrews were strictly forbidden to consult them as the vain but high pretensions of those impostors were derogatory to the honor of God and subversive of their covenant relations with Him as His people.
neither seek after wizards--fortunetellers, who pretended, as the Hebrew word indicates, to prognosticate by palmistry (or an inspection of the lines of the hand) the future fate of those who applied to them.

True fear of God, however, awakens confidence in the Lord and His guidance, and excludes all superstitious and idolatrous ways and methods of discovering the future. This thought prepares the way for the warning against turning to familiar spirits, or seeking after wizards. אוב denotes a departed spirit, who was called up to make disclosures with regard to the future, hence a familiar spirit, spiritum malum qui certis artibus eliciebatur ut evocaret mortuorum manes, qui praedicarent quae ab eis petebantur (Cler.). This is the meaning in Isaiah 29:4, as well as here and in Leviticus 20:6, as is evident from Leviticus 20:27, "a man or woman in whom is an ob," and from 1-Samuel 28:7-8, baalath ob, "a woman with such a spirit." The name was then applied to the necromantist himself, by whom the departed were called up (1-Samuel 28:3; 2-Kings 23:24). The word is connected with ob, a skin. ידּעני, the knowing, so to speak, "clever man" (Symm. γνώστης, Aq. γνωριστής), is only found in connection with ob, and denotes unquestionably a person acquainted with necromancy, or a conjurer who devoted himself to the invocation of spirits. (For further remarks, see as 1-Samuel 28:7.).

Wizards - Them that have entered into covenant with the devil, by whose help they foretel many things to come, and acquaint men with secret things. See Leviticus 20:27; Deuteronomy 18:11; 1-Samuel 28:3, 1-Samuel 28:7, 1-Samuel 28:9; 2-Kings 21:6.