You will place them in a fiery furnace at the time of Your appearing. In His wrath the LORD will engulf them, and the fire will consume them.
David could have given thanks to God in private, but he testified publicly that whatever blessings God conferred upon him redounded to the common good of all His people. Yet above all, the Holy Spirit directs our minds here to Christ, who was the end and perfection of this kingdom, teaching us we cannot be saved except under the Head God Himself appointed.
AI summary
Commenting on Psalm 21:1-13
"Thou shalt make them as a fiery oven in the time of thine anger." They themselves shall be an oven to themselves, and so their own tormentors. Those who burned with anger against thee shall be burned by thine anger. The fire of sin will be followed by the fire of wrath.
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