Be wise now, therefore, O ye kings - This is to be understood as the language of the psalmist. See introduction to the psalm, Section 3. It is an exhortation addressed to the rulers and princes whom the psalmist saw engaged in opposition to the purpose of Yahweh Psalms 2:1-3 - and hence, to all rulers and princes - to act the part of wisdom, by not attempting to resist the plans of God, but to submit to him, and secure his friendship. The psalmist cautions them to take warning, in view of what must certainly come upon the enemies of the Messiah; to cease their vain attempts to oppose his reign, and, by a timely submission to him, to ensure his friendship, and to escape the doom that must come upon his foes. The way of wisdom, then, was not to engage in an attempt in which they must certainly be crushed, but to secure at once the friendship of one appointed by God to reign over the earth.
Be instructed - In your duty to Yahweh and his Anointed One; that is, in the duty of submitting to this arrangement, and lending your influence to promote it. The word used here, and rendered “be instructed,” means properly to chastise, chasten, correct; and it here means, be admonished, exhorted, or warned. Compare Proverbs 9:7; Job 4:3; Psalms 16:7.
Ye judges of the earth - Ye who administer justice; that is, ye rulers. This was formerly done by kings themselves, as it is now supposed to be in monarchical governments, where the judges act in the name of the king. In Republics, justice is supposed to be administered by the people through those whom they have appointed to execute it. The word here is equivalent to rulers, and the call is on those who occupy posts of office and honor not to oppose the purposes of Yahweh, but to bring their influence to the promotion of his designs. At the same time, it cannot be doubted that it is implied that they should seek to be interested personally in his reign.