Gadad has two main uses: (1) to cut or slash oneself as a mourning rite (Jeremiah 16:6; 41:5), a practice forbidden in the Torah (Deuteronomy 14:1), and (2) to gather in troops, to band together for raiding. The self-cutting appears in Baal worship (1 Kings 18:28) when prophets slashed themselves to elicit a response from their god.
The prohibition against self-cutting (gadad) in Deuteronomy 14:1 sets Israel apart from pagan grief practices. Self-mutilation before gods was meant to demonstrate anguish or win divine sympathy. YHWH's prohibition communicates that He does not need such extreme measures — He already knows His people's need and responds to humble prayer, not physical self-harm. The Baal prophets' frantic cutting (1 Kings 18:28) contrasted sharply with Elijah's quiet, trusting prayer (1 Kings 18:36-37) — and God answered only one.