Note: Adapted from  Alden. Here the righteous man in the first three verses is blessed by God with eternal life (whose leaf does not wither and produce fruit ) and this  contrasts with the ungodly in the last three verses who shall perish ( who do not produce fruit and are like useless chaff). B and B’ offer a contrast between the righteous in fellowship with the LORD and the ungodly who are not of that congregation.

A.(1) Blessed is the man
that walketh not in the counsel of the ungodly,
nor standeth in the way of sinners,
nor sitteth in the seat of the scornful.

B.(2) But his delight is in the law of the LORD;
and in his law doth he meditate day and night.

C.(3) And he shall be like a tree planted by the rivers of water,
that bringeth forth his fruit in his season;
his leaf also shall not wither;
and whatsoever he doeth shall prosper.

C’.(4) The ungodly are not so:
but are like the chaff which the wind driveth away.

B’.(5) Therefore the ungodly shall not stand in the judgment,
nor sinners in the congregation of the righteous.

A’.(6) For the LORD knoweth the way of the righteous:
but the way of the ungodly shall perish.