The Hebrew word ethan means ever-flowing, perennial, permanent, or enduring. When used of streams, it describes a wadi that flows year-round rather than drying up in summer. When used of people or things, it signifies strength, durability, and unceasing vitality. It also appears as a proper name (Ethan the Ezrahite, author of Psalm 89).
The image of an ethan stream — one that never runs dry — is powerfully used by Amos to describe God's call for justice to "flow like an ever-flowing stream" (Amos 5:24). Against the backdrop of seasonal wadis that deceive thirsty travelers in summer, the ethan stream represents reliability, covenant faithfulness, and unceasing righteousness. God's character is eternally ethan — He never runs dry.