Dabar is a masculine noun, often used to denote a spoken word, command, or matter. It carries the sense of something that is active and effective.
Cultural context
In ancient Israel, a word was not just a sound but an active force that accomplished what it was sent to do. This reflects the power and authority of God's word.
Theological significance
Isaiah 55:11 emphasizes the effectiveness and purposefulness of God's word, highlighting its role in creation and revelation. It connects to the theme of God's sovereignty and faithfulness.