The Hebrew verb nachash means to divine, to practice omens, to observe signs, to use enchantments. It describes the forbidden occult practice of seeking supernatural knowledge or guidance through signs, omens, or magical rituals rather than through God. Interestingly, this verb shares its root letters with nachash (H5175, the serpent) and nachoshet (H5178, bronze).
The Law strictly forbids divination (nachash) as an abomination (Deuteronomy 18:10; Leviticus 19:26). The prohibition is rooted in the covenant relationship: Israel's God speaks directly through prophets, not through secret signs and omens. To practice divination is to distrust God's sufficiency and to seek power from demonic sources. Ironically, Joseph's silver cup was used for divination (Genesis 44:5), and God could reveal even to pagans — but the ongoing practice is condemned. In the New Testament, the slave girl in Acts 16:16 had a 'spirit of divination' (Python spirit) — cast out by Paul in Jesus' name.