The interpretation timeline
Psalm 143:4 Douay-Rheims

Man is like to vanity: his days pass away like a shadow.

A.D. 430 – 1849 4 witnesses 5 excerpts

Patristic

before A.D. 750
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“"Man is made like unto vanity: his days pass away like a shadow." What vanity? Time, which passeth on, and floweth by. For this "vanity" is said in comparison of the Truth, which ever abideth, and never faileth: for it too is a work of His Hand, in its degree. "For," as it is written, "God filled the earth with His good things." What is "His"? That accord with Him. But all these things, being earthly, fleeting, transitory, if they be compared to that Truth, where it is said, "I Am That I Am," all this which passeth away is called "vanity." For through time it vanisheth, like stroke into the air. And why should I say more than that which the Apostle James said, willing to bring down proud men to humility, "What is," saith he, "your life? It is even a vapour, which appeareth for a little time, and then vanisheth away." ...Work then, though it be in the night, with thine hands, that is, by good works seek God, before the day come which shall gladden thee, lest the day come which shall sadden thee. For see how safely thou workest, who art not left by Him whom thou seekest; "that thy Father which seeth in secret may reward thee openly." ...”
Source
“But if this anomalous state of things were uniform in this life, in which, as the sacred Psalmist says, "Man is like to vanity, his days as a shadow that passeth away,"—so uniform that none but wicked men won the transitory prosperity of earth, while only the good suffered its ills,—this could be referred to the just and even benign judgment of God. We might suppose that they who were not destined to obtain those everlasting benefits which constitute human blessedness were either deluded by transitory blessings as the just reward of their wickedness, or were, in God's mercy, consoled them, and that they who were not destined to suffer eternal torments were afflicted with temporal chastisement for their sins, or were stimulated to greater attainment in virtue. But now, as it is, since we not only see good men involved in the ills of life, and bad men enjoying the good of it, which seems unjust, but also that evil often overtakes evil men, and good surprises the good, the rather on this account are God's judgments unsearchable, and His ways past finding out.”
Source

Scholastic

c. 1100 – 1500
1105
A.D.
Rashi Jewish
1040–1105
“his days are as a fleeting shadow Solomon said (Ecc. 6:12): “that he do them like a shadow,” but he did not explain whether [this refers to] the shadow of a palm or the shadow of a wall, which are permanent. His father already explained, “as a fleeting shadow,” the shadow of a flying bird.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“Man is like to vanity,.... Is vanity itself, in every age, state, and condition; yea, in his best estate, Psa 39:5; or, "to the breath" (h) of the mouth, as Kimchi; which is gone as soon as seen almost: or, to a vapour (i); to which the life of man is compared, Jam 4:14; his days are as a shadow that passeth away; as the former denotes the frailty and mortality of man, this the shortness of his duration; his days fleeing away, and of no more continuance than the shadow cast by the sun, which presently declines and is gone. (h) "halitui", Muis; so Kimchi. (i) "Vapori", Cocceius; so the Syriac and Arabic versions.”
Source
1849
A.D.
1774–1849
“Vanity. Hebrew hebel, “nothing, a vapour,” &c., Ecclesiastes i. 1., and James iv. 15. (Haydock) — Our lives resemble a shadow, which is the less distinct, the more it increases. (Berthier) — As it cannot subsist of itself, so neither can man without God. (Worthington)”
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.