Imamat 19:31

19:31 Do not turn to the spirits of the dead and do not seek familiar spirits ¹  to become unclean by them. I am the Lord your God.

Ulangan 18:11

18:11 one who casts spells, ²  one who conjures up spirits, ³  a practitioner of the occult, ⁴  or a necromancer. ⁵ 

[19:31]  ¹ sn The prohibition here concerns those who would seek special knowledge through the spirits of the dead, whether the dead in general or dead relatives in particular (i.e., familiar spirits; see J. E. Hartley, Leviticus [WBC], 321, and B. A. Levine, Leviticus [JPSTC], 134). Cf. Lev 20:6 below.

[18:11]  ² tn Heb “a binder of binding” (חֹבֵר חָבֶר, khover khaver). The connotation is that of immobilizing (“binding”) someone or something by the use of magical words (cf. Ps 58:6; Isa 47:9, 12).

[18:11]  ³ tn Heb “asker of a [dead] spirit” (שֹׁאֵל אוֹב, sho’el ’ov). This is a form of necromancy (cf. Lev 19:31; 20:6; 1 Sam 28:8, 9; Isa 8:19; 19:3; 29:4).

[18:11]  ⁴ tn Heb “a knowing [or “familiar”] [spirit]” (יִדְּעֹנִי, yiddÿ’oniy), i.e., one who is expert in mantic arts (cf. Lev 19:31; 20:6, 27; 1 Sam 28:3, 9; 2 Kgs 21:6; Isa 8:19; 19:3).

[18:11]  ⁵ tn Heb “a seeker of the dead.” This is much the same as “one who conjures up spirits” (cf. 1 Sam 28:6-7).