Sāchāh (שָׂחָה) means to swim — to move through water. Rare in the Hebrew Bible, used in a striking metaphor of helplessness.
Isaiah 25:11: 'They will spread out their hands as a swimmer spreads hands to swim. God will bring down their pride.' The context is judgment on Moab — the proud nation flailing helplessly. Pride makes us think we can swim any depth; God reminds us He controls the waters. Ezekiel 47:5 uses a related image: the river from the temple deepens until it becomes 'deep enough to swim in' — representing the ever-increasing flow of God's life-giving grace.