Verse 21. Who knoweth the spirit of man - I think the meaning of this important verse is well taken by the above able writer: - The nobler part of man, 'tis true, survives The frail corporeal frame: but who regards The difference? Those who live like beasts, as such Would die, and be no more, if their own fate Depended on themselves. Who once reflects, Amidst his revels, that the human soul, Of origin celestial, mounts aloft, While that of brutes to earth shall downward go?" The word jwr ruach, which is used in this and the nineteenth verse, has two significations, breath and spirit. It signifies spirit, or an incorporeal substance, as distinguished from flesh, or a corporeal one, 1 Kings xxii. 21, 22, and Isa. xxxi. 3. And it signifies the spirit or soul of man, Psalm xxxi. 6; Isa. lvii. 16, and in this book, chap. xii. 7, and in many other places. In this book it is used also to signify the breath, spirit, or soul of a beast.
While it was said in ver. 19, they have all one breath, i.e., the man and the beast live the same kind of animal life; in this verse, a proper distinction is made between the jwr ruach, or soul of man, and the jwr ruach, or soul of the beast: the one goeth upwards, the other goeth downwards. The literal translation of these important words is this: "Who considereth the jwr ruach) immortal spirit of the sons of Adam, which ascendeth? it is from above; ( hl[ml ayh hi lemalah;) and the spirit or breath of the cattle which descendeth? it is downwards unto the earth," i.e., it tends to the earth only. This place gives no countenance to the materiality of the soul; and yet it is the strongest hold to which the cold and fruitless materialist can resort.
Solomon most evidently makes an essential difference between the human soul and that of brutes. Both have souls, but of different natures: the soul of man was made for God, and to God it shall return: God is its portion, and when a holy soul leaves the body, it goes to paradise. The soul of the beast was made to derive its happiness from this lower world. Brutes shall have a resurrection, and have an endless enjoyment in a new earth. The body of man shall arise, and join his soul that is already above; and both enjoy final blessedness in the fruition of God. That Solomon did not believe they had the same kind of spirit, and the same final lot, as some materialists and infidels say, is evident from chap. xii. 7: "The spirit shall return unto God who gave it."
Verse 22. A man should rejoice in his own works - Do not turn God's blessings into sin by perverseness and complaining; make the best of life.
God will sweeten its bitters to you, if you be faithful. Remember this is the state to prepare for glory; and the evils of life may be so sanctified to you as to work for your good. Though even wretched without, you may be happy within; for God can make all grace to abound towards you. You may be happy if you please; cry to God, who never rejects the prayer of the humble, and gives his Holy Spirit to all them that ask him.