Have I not commanded you? Be strong and courageous. Do not be afraid; do not be discouraged, for the Lord your God will be with you wherever you go.”
Encouragement from God’s commandment (v. 9). God’s commandments are still God’s enablements for those who obey Him by faith. Gabriel’s words to Mary are as true today as when he spoke them in Nazareth: “For with God nothing shall be impossible” (Luke 1:37). I especially like the translation of this verse found in the American Standard Version (1901): “For no word from God shall be void of power.” The very word that God speaks has in it the power of fulfillment if we will but trust and obey!
In the years to come, whenever Joshua faced an enemy and was tempted to be afraid, he would remember that he was a man with a divine commission — and his fears would vanish. Whenever things went wrong and he was tempted to be dismayed, he would recall God’s command — and take new courage. Like Moses before him, and Samuel and David after him, Joshua had a divine mandate to serve the Lord and do His will-and that mandate was sufficient to carry him through.
(from The Bible Exposition Commentary: Old Testament © 2001-2004 by Warren W. Wiersbe. All rights reserved.)