John Gill Commentary Daniel 4:26

"And whereas they commanded to leave the stump of the roots of the tree; thy kingdom shall be sure unto thee, after that thou shalt have known that the heavens do rule." — Daniel 4:26 (ASV)

And whereas they commanded to leave the stump of the tree
roots
That is the watchers and the Holy Ones; or it was commanded: this was the order given by the most High:

your kingdom shall be sure unto you ;
signifying that another king should not be set up in his place; and though the kingdom and administration of it would depart from, him for a while, yet it would be restored again, and be firm and stable:

after that you shall have known that the heavens do rule ;
that is, that God, who is the Maker of the heavens, and dwells there, is known and acknowledged by you to rule on the earth; from the government of which he was desirous of excluding him, and taking it to himself; see (Luke 15:18) .