Charles H. Spurgeon on Psalms 1:1

Whole Psalm. As the book of the Canticles is called the Song of Songs by a Hebraism, it being the most excellent, so this Psalm may not unfitly be entitled, the Psalm of Psalms, for it contains in it the very pith and quintessence of Christianity. What Jerome saith on St. Paul's epistles, the same may I say of this Psalm; it is short as to the composure, but full of length and strength as to the matter. This Psalm carries blessedness in the frontpiece; it begins where we all hope to end: it may well be called a Christian's Guide, for it discovers the quicksands where the wicked sink down in perdition, and the firm ground on which the saints tread to glory. —Thomas Watson's Saints Spiritual Delight, 1660.

This whole Psalm offers itself to be drawn into these two opposite propositions: a godly man is blessed, a wicked man is miserable; which seem to stand as two challenges, made by the prophet: one, that he will maintain a godly man against all comers, to be the only Jason for winning the golden fleece of blessedness; the other, that albeit the ungodly make a show in the world of being happy, yet they of all men are most miserable. —Sir Richard Baker, 1640

I have been induced to embrace the opinion of some among the ancient interpreters (Augustine, Jerome, etc.), who conceive that the first Psalm is intended to be descriptive of the character and reward of the JUST ONE, i.e. the Lord Jesus. —John Fry, B.A., 1842

The psalmist saith more to the point about true happiness in this short Psalm than any one of the philosophers, or all of them put together; they did but beat the bush, God hath here put the bird into our hand. John Trapp, 1660