For the king trusts in the LORD; through the loving devotion of the Most High, he will not be shaken.
PSALM 21. This psalm contains a public and solemn thanksgiving for the prosperous and happy condition of the king. Its subject is almost the same with that of the preceding. “What was anticipated in the preceding psalm, the present poem appears to celebrate as having been achieved.” — Drake’s Harp of Judah.
Commenting on Psalm 21:1-13
"For the king trusteth in the Lord." Our Lord, like a true King and leader, was a master in the use of the weapons, and could handle well the shield of faith, for he has set us a brilliant example of unwavering confidence in God.
The psalmist, having taught his people to look back with joy and praise on what God had done for him and them, here teaches them to look forward with faith, and hope, and prayer, upon what God would further do for them: The king rejoices in God (Psa 21:1), and therefore we will be thankful; the king trusteth in God (Psa 21:7), therefore will we be encouraged.
Commenting on Psalm 21:7-13