Psalms 1:6

For the LORD knoweth the way of the righteous: but the way of the ungodly shall perish.

The way of the righteous is the life of the one who delights in the law of the Lord and meditates on it day and night, growing and prospering like a tree planted by abundant water that brings forth fruit in its season with leaves that do not fade. The Lord knows and watches over and regards that life and course and way of righteousness.

The ungodly are the opposite, like light, weightless chaff driven away by the wind, unable to stand in the judgment or to remain among the righteous. The verse completes the contrast by declaring that the course and way of the ungodly ends in ruin and destruction and perishes.