14 I have seen all the works that are done under the sun; and, behold, all is vanity and vexation of spirit.
[AD 253] Origen of Alexandria on Ecclesiastes 1:14
This then is the “vanity” to which the creation was subjected, and above all that creation which is certainly the greatest thing in this world and which holds a distinguished preeminence by reason of its function. That is, the sun, moon and stars are said to have been subjected to vanity, because they were clothed with bodies and set to perform the task of giving light to the human race. And this creation, Scripture says, was subjected to vanity “not of its own will.” For it did not undertake a service to vanity by the exercise of free will but in obedience to the wish of him who was subjecting it, because he who subjected it promised those who were being given over unwillingly to vanity that on the fulfillment of their splendid work of service they should be delivered from this bondage of corruption and vanity, when the time of redemption “of the glory of the sons of God” should have come. Having received this hope, and looking for the fulfillment of this promise, the entire creation now in the meantime “groans together” with us (for it even has sympathy with those whom it serves) and “is in pain together,” while in patience it hopes for what has been promised.

[AD 390] Gregory of Nazianzus on Ecclesiastes 1:14
“I have seen everything,” says Ecclesiastes. I have reviewed in my mind all human things, wealth, luxury, power, glory that is not stable, wisdom that eludes us more often than it is mastered; again pleasure, again wisdom, often returning full circle to the same things, delights of the belly, orchards, numbers of slaves, a multitude of possessions, male and female table servants, singing men and singing women, arms, henchmen, nations at one’s feet, revenues flowing in, the pride of royalty, all life’s superfluities and necessities, in which I surpassed all the kings who were before me. And after all this what is his judgment? “All is vanity of vanities, all is vanity and vexation of spirit,” that is, a kind of irrational impulse of soul and distraction of man who has been condemned to this perhaps because of the original fall. But “hear all the conclusion of my discourse,” he says; “fear God.” Through this he ceases from perplexity. And this alone is your gain from life here, to be brought through the confusion of things that are seen and unstable to things which are firm and immovable. ON HIS BROTHER ST.

[AD 395] Gregory of Nyssa on Ecclesiastes 1:14
He came, then, to enquire by his own wisdom what has come about under the sun, what the confusion is of things here on earth, how being became the slave of nonbeing, how the unreal dominates being. And he saw that evil distress God gave to the sons of man, for them to be distressed with. This does not mean, as one might assume at first glance, that it is devout to think that God gave evil distress to people, for then the responsibility for ills would be laid on him.… What the more devout understanding is disposed to think is this: that the good gift of God, that is, freedom of action, became a means to sin through the sinful use humankind made of it. For unfettered free will is good by nature, and nobody would reckon among good things anything that was constrained by the yoke of necessity. But that free impulse of the mind rushing unschooled toward the choice of evil became a source of distress for the soul, as it was dragged down from the sublime and honorable toward the urges of the natural passions.… [Therefore] a correct understanding does not conclude that anything bad has been put in human nature by God but blames our capacity to choose, which is in itself a good thing. [It is] a gift of God granted to our nature, but through folly it has become a force tipping the balance the opposite way.
[AD 395] Gregory of Nyssa on Ecclesiastes 1:14
Ecclesiastes has come to search through his own wisdom those actions done under the sun, their confusion, why things are subject to nonexistence and how that which is insubstantial prevails against being. He knew that “God has given to the sons of men an evil trouble to be vexed with.” This is not a pious deed we can readily understand because God has given an evil to the sons of men in order to trouble them; and so one may attribute the cause of evil to God.… A more pious understanding suggests that God bestows upon man the gift of free will which he abused and then became an instrument for sin. This free will is good and subject to no one, while anything subject to necessity should not be counted as good. But any impulse coming from the mind is free; it distracts the soul to choose evil and pulls it down to passion from the lofty honors it had received.… An accurate understanding of these verses does not mean that human nature lacks anything unbecoming from God; rather, they censure our power of free choice which in itself is good and a gift bestowed by God to human nature. But as a result of indiscretion, free will inclines towards the opposite way.

[AD 420] Jerome on Ecclesiastes 1:14
"I have
seen all the deeds done underneath the sun, and behold all is futile and a
vexation of the spirit." We are compelled here by necessity to examine
the Hebrew words more closely than we wish.
It is also not possible to know the real meaning of the text, unless we
learn it through studying the original Hebrew words. Aquila and Theodotion translate "routh
"as the Greek "nomen", Symmachus
has "boskesin". The Septuagint does not
express the Hebrew meaning, but the Syriac, as shown in the Greek word "proairesin". Therefore either "nome", or "boskesis", is the
noun coming from "vexation." "Proairesis
"sounds more like 'will' than 'vexation'.
Every single man however is said to do what he "wishes", and what seems right to him; and men are borne with different dispositions (i.e.
good and wicked) of their own free will.
And all things under the sun are vain, when we displease each other by
doing what is the greatest good and greatest evil. A Hebrew, who was instructing me as I read
the Holy Scriptures, said to me that above the word "routh" was written ""it
means rather suffering and wickedness in this place than vexation and will"",
and the meaning does not come from the evil which is contrary to good, but from
that which is written in the Gospel: ""Sufficient
to the day is its wickedness."" [Matth. 6, 34.] The Greeks call this more significantly "kakouchian", so the verse essentially
means: "I have considered all things, which are done in the world, and I
discovered nothing except vanity and wickedness, that is distress of the soul,
by which the spirit is afflicted in contrary thoughts.

[AD 430] Augustine of Hippo on Ecclesiastes 1:14
We read in Scripture concerning the striving after temporal things, “All is vanity and presumption of spirit,” but presumption of spirit means audacity and pride. Usually also the proud are said to have great spirits, and rightly, inasmuch as the wind also is called spirit. And hence it is written, “Fire, hail, snow, ice, spirit of tempest.” But, indeed, who does not know that the proud are spoken of as puffed up, as if swelled out with wind? And hence also that expression of the apostle, “Knowledge puffs up, but charity edifies.” And “the poor in spirit” are rightly understood here, as meaning the humble and God-fearing, that is, those who have not the spirit which puffs up. Nor ought blessedness to begin at any other point whatever, if indeed it is to attain unto the highest wisdom. “But the fear of the Lord is the beginning of wisdom”; for, on the other hand also, “pride” is entitled “the beginning of all sin.” Let the proud, therefore, seek after and love the kingdoms of the earth, but “blessed are the poor in spirit, for theirs is the kingdom of heaven.”

[AD 749] John Damascene on Ecclesiastes 1:14
So, following the teachings of these blessed saints, we utterly renounce these corruptible and perishable things of life, wherein may be found nothing stable or constant, or that continues in one stay. But all things are vanity and vexation of spirit, and many are the changes that they bring in a moment, for they are slighter than dreams and a shadow, or the breeze that blows the air. Small and short-lived is their charm, that is after all no charm, but illusion and deception of the wickedness of the world; which world we have been taught to love not at all but rather to hate with all our heart. Yes, and truly it is worthy of hatred and abhorrence; for whatsoever gifts it gives to its friends, these in turn in passion it takes away and shall hand over its victims, stripped of all good things, clad in the garment of shame, and bound under heavy burdens, to eternal tribulation. And those again whom it exalts, it quickly abases to the utmost wretchedness, making them a footstool and a laughing stock for their enemies. Such are its charms, such its bounties.