Smashing Wave is a level 4 spell from the Priest Scroll in Icewind Dale, which is added with Heart of Winter.
Description[]
| “ | This spell summons a 5-ft. wide wave of water that moves in the direction willed by the caster, striking all in its path with massive force. The wave deals 4d10 points of crushing damage; in addition, struck creatures may be either stunned (25% chance) or knocked unconscious (5% chance) for 2 rounds. If the creature struck makes a successful Save vs. Breath Weapon, the damage is reduced by half and the creature avoids being stunned or knocked unconscious. | ” |