20 Shall not the day of the LORD be darkness, and not light? even very dark, and no brightness in it?
[AD 420] Jerome on Amos 5:18-20
(Verse 18-20.) Woe to those who long for the day of the Lord! Why do you long for it? That day will be darkness, not light. It will be as though a man fled from a lion only to meet a bear, as though he entered his house and rested his hand on the wall only to have a snake bite him. Will not the day of the Lord be darkness, not light— pitch-dark, without a ray of brightness? Woe to those who long for the day of the Lord! Why do you long for the day of the Lord? And this is darkness, and not light. As if a man should flee from the face of a lion, and a bear should meet him: or enter into the house, and lean with his hand upon the wall, and a serpent should bite him. Shall not the day of the Lord be darkness, and not light? and obscurity, and no brightness in it? Lest the tribe of Juda be thought to neglect men of his own stock, and to confer the speech of prophecy upon the ten tribes: Thou also shalt go to the king against Babylon, and shalt speak to him: There are gathered together all the kings of the earth against Jerusalem: how art thou fallen, thou virgin, daughter of Babylon, to be destroyed? Shall not day overtake thee suddenly, and thou perish with the sword? For there is not so much evil in the injury of captivity, as there is good in the things which the Lord promises after captivity: to which the prophet replied that it is in vain for them to wait for what will happen a long time after, in the coming of the Son of God after seventy years of captivity in Babylon, which will be followed by devastation, poverty, and countless miseries. For, he says, when those fleeing from the face of Nebuchadnezzar meet Assuerus, under whom the story of Esther is narrated, or when the empire of the Assyrians and Chaldeans is destroyed, the Medes and Persians will rise up. And when, during the reign of Cyrus, you returned, and at the command of Darius began to build the house of the Lord, and you placed all your trust in the temple, so that you may find rest in it and weary hands may rest upon its walls, then Alexander, the king of the Macedonians, also known as Antiochus Epiphanes, will come and dwell in the temple and will bite you like a snake, not outside in Babylon and Susa, but within the borders of the holy land (or yours). By these things it is proven that the day which you desire is not one of light and joy, but of darkness and sorrow. We have briefly stated these things according to history, so as not to completely leave the opinion of the Jews untouched. However, there is no doubt that all of our people understand the day of darkness, the day of judgment, about which Sophonias also writes: The great day of the Lord is near, it is also very swift: the voice of the day of the Lord is bitter and harsh (Sophon. I, 14). And Isaiah says: Behold, the day of the Lord comes, a day of incurable rage and wrath, to make the earth a desolation and to destroy sinners from it (Is. XIII, 9). At the same time, the confidence of the proud is shaken, who, in order to appear just in the eyes of men, usually wait for the day of judgment and say: Would that the Lord would come, that we may be allowed to be dissolved and be with Christ (Phil. I), imitating the Pharisee who spoke in the Gospel (Lk. XVIII, 11, 12): God, I give thanks to you, because I am not like other men, robbers, unjust, adulterers, and like this tax collector. They fast twice on the Sabbath: they give tithes of all that they possess. For from this very thing, because they long for the day of the Lord and do not fear it, they are judged worthy of punishment, because there is no one without sin among men, and the stars are unclean before him (Job 25). And he concluded all things under sin, so that he might have mercy on all (Galatians 3). Therefore, since no one can judge the judgment of God, and we will also have to give an account of every idle word (Matthew 12): and Job offered sacrifices daily for his children, lest perhaps they might think anything perverse against the Lord (Job 1), what audacity is it to hear among the Corinthians: You reign without us (I Corinthians 4, 8): and I wish you did reign, that we also might reign with you. Certainly, if their own conscience did not prick them, they ought to imitate Paul saying: 'Who is scandalized, and I am not on fire?' (2 Cor. 2:29) and to be concerned for all, so that, as lovers of themselves, they may not desire the torments of others, as if they themselves were the rulers, just as someone would want their homeland and city to be destroyed so that they alone may enjoy the friendship of the victors. We often say in times of distress and tribulation: 'Oh, if only it were allowed for me to depart from this body and be liberated from the miseries of this world', not knowing that as long as we are in this flesh, we have a place for repentance; but if we depart, we will hear that of the Prophet: 'But who will confess to you in hell?' (Ps. 6:6). This is the sadness of the world, which leads to death, as the Apostle does not want to perish the one who has fornicated with his father's wife (I Cor. V), as Judas perished unfortunate, who connected betrayal and murder with even greater sadness (Matth. XXVII), and murder worse than all other murders: so that where he thought to find a remedy, and death to be an end to his troubles, there he would find a lion and a bear and a snake. By these names it seems to me that either different punishments are being signified, or the devil himself, who is rightly called lion and bear and snake. And when we think that Isaiah says: Go, my people, into your chambers; shut the door, hide yourself for a little while, until the wrath of the Lord passes (Isa. XXVI, 20), and be as if in our house, as if resting in hell: then the snake will bite us, which in this place is called Nahas, and in Job is called Leviathan. We learn more fully about its nature and terror in the very volume itself. However, in the darkness and shadows that are contrary to light and splendor, the diversity of torments is explained.

[AD 407] John Chrysostom on Amos 5:20-24
This brings us to a conclusion on another matter of great importance. The observances regarding sacrifices, sabbaths, new moons, and all such things prescribed by the Jewish way of life of that day—they are not essential. Even when they were observed they could make no great contribution to virtue; nor when neglected could they make the excellent person worthless or degrade in any way the sanctity of his soul. People of old, while still on earth, manifested by their piety a way of life that rivals the way the angels live. Yet they followed none of these observances, they slew no beasts in sacrifice, they kept no fast, they made no display of fasting. They were so pleasing to God that they surpassed this fallen human nature of ours and, by the lives they lived, drew the whole world to a knowledge of God.

[AD 651] Braulio of Zaragoza on Amos 5:20-24
I am pierced by one wound and tortured with much grief, the bond of bitterness does not permit the tongue to perform its function, and it is easier to weep than to talk. Lo, one affliction comes upon another affliction and contrition upon contrition, “as if a man were to flee from a lion, and a bear should meet him,” or howl at being struck by a scorpion, “and a snake should bite him,” so completely am I dejected and afflicted with the misery of sorrow. I confess, madam, that every time I try to write to you about the passing of our lady Basilla of blessed memory, I am overcome with bitterness and experience a dullness in my mind, a heaviness in my sense and slowness in my tongue, because while I was occupied with grief, my mind was moved by death.