The Arnon is a river forming a significant geographic boundary in the ancient Near East — the traditional border between Moab and Amorite territory, and later between Reuben and Moab. Its name may relate to a root meaning 'to roar' or 'rushing.'
The Arnon appears repeatedly in the Exodus and conquest narratives as a boundary God directed Israel to respect or cross. Numbers 21 records Israel passing near Arnon on their way to Canaan. The river marks the line between Israel's territory and that of surrounding nations — a tangible sign of God's precise ordering of the nations' boundaries. Acts 17:26 echoes this principle: God 'determined allotted periods and the boundaries of their dwelling place.'