The remainder of the psalm has three thoughts--the real nullity of such lives, their consequent disappearance in "the judgment," and the ground of both the blessedness of the one type of character and the vanishing of the other in the diverse attitude of God to each. Nothing could more vividly suggest the essential nothingness of the "wicked" than the contrast of the leafy beauty of the fruit-laden tree and the chaff, rootless, fruitless, lifeless, light, and therefore the sport of every puff of wind that blows across the elevated and open threshing floor.
Such is indeed a true picture of every life not rooted in God and drawing fertility from Him. It is rootless; for what hold-fast is there but in Him? or where shall the heart twine its tendrils if not round God's stable throne? or what basis do fleeting objects supply for him who builds elsewhere than on the enduring Rock? It is fruitless; for what is fruit? There may be much activity and many results satisfying to part of man's nature and admired by others. One fruit there will be, in character elaborated. But if we ask what ought to be the products of a life, man and God being what they are in themselves and to each other, we shall not wonder if every result of godless energy is regarded by "those clear eyes and perfect judgment" of heaven as barrenness. In the light of these higher demands, achievements hymned by the world's acclamations seem infinitely small, and many a man, rich in the apparent results of a busy and prosperous life, will find to his dismayed astonishment that he has nothing to show but unfruitful works of darkness. Chaff is fruitless because lifeless.
Its disappearance in the winnowing wind is the consequence and manifestation of its essential nullity. "Therefore" draws the conclusion of necessary transiency. Just as the winnower throws up his shovel full into the breeze, and the chaff goes fluttering out of the floor because it is light, while the wheat falls on the heap because it is solid, so the wind of judgment will one day blow and deal with each man according to his nature. It will separate them, whirling away the one, and not the other. "One shall be taken and the other left." When does this sifting take effect? The psalmist does not date it. There is a continually operative law of retribution, and there are crises of individual or national life, when the accumulated consequences of evil deeds fall on the doers. But the definite article prefixed to "judgment" seems to suggest some special "day" of separation. It is noteworthy and perhaps illuminative that John the Baptist uses the same figures of the tree and the chaff in his picture of the Messianic judgments, and that epoch may have been in the psalmist's mind. Whatever the date, this he is sure of--that the wind will rise some time, and that, when it does, the wicked will be blown out of sight. When the judgment comes, the "congregation of the righteous"--that is, the true Israel within Israel, or, to speak in Christian language, the true invisible Church--will be freed from admixture of outward adherents, whose lives give the lie to their profession. Men shall be associated according to spiritual affinity, and "being let go," will "go to their own company" and "place," wherever that may be.
The ground of these diverse fates is the different attitude of God to each life. Each clause of the last verse really involves two ideas, but the pregnant brevity of style states only half of the antithesis in each, suppressing the second member in the first clause and the first member in the second clause, and so making the contrast the more striking by emphasising the cause of an unspoken consequence in the former, and the opposite consequence of an unspoken cause in the latter. "The Lord knoweth the way of the righteous [therefore it shall last]. The Lord knoweth not the way of the wicked [therefore it shall perish]." The way which the Lord knows abides. "Know" is, of course, here used in its full sense of loving knowledge, care, and approval, as in "He knoweth my path" and the like sayings. The direction of the good man's life is watched, guarded, approved, and blessed by God. Therefore it will not fail to reach its goal. They who walk patiently in the paths which He has prepared will find them paths of peace, and will not tread them unaccompanied, nor ever see them diverging from the straight road to home and rest. "Commit thy way unto the Lord," and let His way be thine, and He shall make thy way prosperous.