John Gill Commentary Ecclesiastes 3:19

"For that which befalleth the sons of men befalleth beasts; even one thing befalleth them: as the one dieth, so dieth the other; yea, they have all one breath; and man hath no preeminence above the beasts: for all is vanity." — Ecclesiastes 3:19 (ASV)

For that which befalls the sons of men befalls beasts, &c.] Aben Ezra says this verse is according to the thoughts of the children of men that are not wise; but rather the wise man says what he does according to his own thoughts, and proceeds to prove the likeness and equality of men and beasts;

even one thing befalls them; the same events belong to one as to another; the same diseases and disasters, calamities and distresses: Noah's flood carried away one as well as another; they both perished in it; several of the plagues of Egypt were inflicted on both; and both are beholden to God for their health, preservation, and safety; see (Genesis 7:21) (Exodus 8:18) (Exodus 9:9Exodus 9:25) (Psalms 36:6);

as the one dieth, so dieth the other; the Targum compares a wicked man and an unclean beast together, in the former clause; and paraphrases this after this manner, ``as an unclean beast dies, so dies he who is not turned to repentance before his death:'' he dies unclean in his sins, stupid, senseless; no more thoughtful of his future state, and of what will become of his precious and immortal soul, than a beast that has none; see (Psalms 49:14); perhaps unjust judges, persecuting tyrants, may particularly be regarded: who, though princes, shall not only die like men, but even like beasts, (Psalms 82:7);

yea, they have all one breath; the same vital breath, or breath of life, which is in the nostrils of the one as of the other; they breathe and draw in the same air, and have the same animal and vegetative life, and equally liable to lose it, (Genesis 2:7) (7:22);

so that a man has no preeminence above a beast: he has reason and speech, which a beast has not; which gives him a preference to them, did he make a right use of them; but, as an animal, he has no preeminence, being liable to the same accidents, and to death itself: the Targum excepts the house of the grave, man being usually buried when he dies, but a beast is not: yea, in some things a beast has the preeminence of a man; at least some have, in strength, agility, quickness of the senses

for all [is] vanity; all the gratifications of the senses; all riches, honours, pleasures, power, and authority, especially when abused.