G-d's "regret": Isaiah 23:13; Sukah 52B;

Isaiah 23:13:

Behold, the land of the Chaldeans, this people was not. Assyria founded it for ships, they set up their towers, they demolished its palaces, they made it a ruin.

Rashi (ad loc.):

"this people was not" -- They are not fitting to have been a people... They are an aberrant people among mankind, whose creation the Holy One Blessed is He regrets, as [our Sages] taught: "There are three [whose creation] the Holy One Blessed is He regrets," in Tractate Sukah (52B).

Sukah 52B:

Rav Chana bar Acha said, and some say it was taught in the Academy of Rav: There are four that the Holy One Blessed is He regrets having created, and they are: the Chaldeans, the Evil Inclination, Ishmael, Exile.

Iyun Yaakov (ad loc.):

"the Holy One Blessed is He regrets" -- Even though the Holy One Blessed is He knows the future and regret does not apply to Him, nevertheless we find [similarly stated] in the Torah, "G-d regretted that He made man on earth," for the Torah speaks in human terms. The meaning of this statement is that it would be fitting to regret [creating] these, were it not for the fact that He did so in order that Israel would return in repentance, and the Evil Inclination was created to increase the reward for the righteous who vanquish it.

Isaiah 22:1-2; Taanith 29A

Isaiah 22:1-2:

A prophecy concerning the Valley of Visions: For what reason is it, now, that you have all gone to the rooftops? [City that was] filled with the shouts [of masses of people], city of rabble, city of excited outcry, your dead are not the dead of the sword, nor the casualties of war."

Taanith 29A:

When the Temple was destroyed the first time, groups of the priestly youth gathered, with the keys to the Sanctuary in their hands, and they ascended to the roof of the Sanctuary and said before Him: 'Master of the Universe, since we did not merit to be faithful treasurers before You, behold, the keys are given over to You." [With that,] they threw them upward. A sort of hand emerged and took them, and they (the priests) jumped and fell into the fire. Upon them Isaiah lamented, "A prophecy concerning the Valley of Visions: For what reason, now, has all of you ascended to the rooftops? [City that was] filled with the shouts [of masses of people], city of rabble, city of excited outcry, your dead are not the dead of the sword, nor the casualties of war" (Isaiah 22:1-2).

Yerushalmi Shekalim 6:2:

At the time Nebuchadnezzar ascended to here (Israel), he came and settled in Daphne near Antioch. The Great Sanhedrin came out toward him and said to him: "Has the time come for this Temple to be destroyed?" He said to them: "Give to me the one whom I appointed king over you and I shall go." They came and said to Yehoyachin, King of Judah: "Nebuchadnezzar wants you." When he heard this from them, he took the keys of the Holy Temple and ascended to the roof of the Sanctuary. He said before Him: "Master of the Universe, in the past we were faithful to You and Your keys were given over to us. Now that we are not faithful, behold, Your keys are given over to You." Two amoraim (Talmudic teachers) [disputed what happened next]. One said [Yehoyachin] threw [the keys upwards] and they have not yet descended, and one said a sort of hand came and took them from his hand. When all the noblemen of Judah saw this, they ascended to the tops of their roofs, fell and died. So it is written (Isaiah 22:1): "A prophecy concerning the Valley of Visions: For what reason is it, now, that you have all gone to the rooftops?"

Va-Yikra Rabah 19:6:

When Nebuchadnezzar killed [King Yehoyakim], he appointed [Yehoyakim's] son Yechonyah (Yehoyachin) in his stead and descended to Babylon. All of the people of Babylon came forth to praise him. They said to him, "What have you done?" He said to them, "Yehoyakim rebelled against me. I killed him and appointed Yechonyah his son in his stead." They said to him, "There is a parable: Don't raise a good puppy from a bad dog. A bad puppy from a bad dog -- how much more so!" Immediately he hearkened to them  and ascended and settled in Daphne of Antioch. The Great Sanhedrin descended toward him and said to him: "Has the time come for this Temple to be destroyed?" He said to them: "No, however the one whom I have appointed king over you -- give him to me and I shall go on my way." They went and said to Yechonyah: "Nebuchadnezzar wants you." What did he do? He stood up and gathered all the keys of Holy Temple and ascended to the top of the roof and said: "Master of the Universe, since we have not merited to be treasurers before You, until now we were faithful masters of households before You; from now on, behold, Your keys are before You." Two amoraim [disputed what happened next]. One said a sort of hand of fire descended and took them from him, and one said from the time he threw them they have not yet descended. What did the distinguished men of Israel do? They ascended to the tops of their roofs and fell and died. So it is written (Isaiah 22:1): "A prophecy concerning the Valley of Visions: For what reason, now, have you all ascended to the rooftops?" What did Nebuchadnezzar do? He seized [Yechonyah] and incarcerated him in prison, and anyone who was incarcerated in [Nebuchadnezzar]'s days would never leave there... Yehoyachin was exiled and the Great Sanhedrin was exiled with him...

Jerusalem called "Valley of Visions"; Jerusalem is Gate of Heaven

Isaiah 22:1:

A prophecy concerning the Valley of Visions...

 Rashi:

"the Valley of Visions" - This is  Jerusalem, the valley about which most prophecies were prophesied.

Rashi to Taanith 29A:

"Valley of Visions" -- the valley in which they would prophesy... Alternatively, Jerusalem, for all would gaze at her.

Etz Yoseph to Taanith 29A:

In Pethichta 24 of Echah Rabatha it states: "'A prophecy concerning the Valley of Visions' -- the valley about which all the prophets prophesy." (The meaning is that this prophecy was said concerning Jerusalem. She is called "the Valley of Visions" for all the visionaries, i.e. the prophets, prophecy concerning the return of her inhabitants. [The prophet] called her a valley even though it is a mountain to connote derisively, for her inhabitants cast her down with their evil, making her from a mountain into a valley, for she is no longer worthy to be called a mountain, rather, a valley.) "The valley from which all the prophets derive." According to this interpretation, the term "valley" connotes the high quality of the city and its praise, for just as the valley receives rainwater, so is Jerusalem fit to receive the flow of prophecy, for there is the Gate of Heaven and from there comes prophecy to the prophets, for "all the prophets" (i.e. most) derive from her, as R' Yochanan said: "Any prophet whose city's name was not specified was a Jerusalemite."

Dearest Wives-Here’s What We Wished You Knew | Jewocity Blog

Dearest Wives-Here’s What We Wished You Knew | Jewocity Blog

Seirim are demons

Isaiah 13:21:

Mongooses will lay there, and their houses will be filled with ochim; benoth yaanah will dwell there, and seirim will dance there.

Rashi:

"seirim" -- demons.

Israel compared to stars

Isaiah 13:14:

And you (Babylonia/Nebuchadnezzar) said, "I will ascend, over the stars of G-d I will raise my throne..."

Rashi:

"the stars of G-d" -- Israel.

Monkey Tales

Everybody knows and loves that good old children's classic Caps for Sale. In this ironic tale, the protagonist, a cap salesman who has the peculiar habit of wearing his wares in a towering pile on his head, takes a nap beneath a tree. When he awakes, he finds his hats missing and discovers that a band of monkeys hanging about the tree above him have all adorned themselves with his caps. He coaxes them to return them to him with a wave of his finger, his fists, and with stamping feet, but his attempts are only met with the monkeys mirroring and mimicking his every move. Finally, he angrily throws his hat to the floor in disgusted defeat, and of course, the monkeys do the same, and the man has his hats back. Caps for Sale was published in 1938, yet, I discovered, its plot is based on a tale quite a bit older.

The Talmud (Megilah 3A) imparts the following wisdom (comments in parenthes

is are my own):

"Ravina said: ...If someone becomes frightened, even though he does not see (the source of his fright), his guardian angel does see it. (I.e. A person will become subconsciously aware of a spiritual danger although he cannot consciously detect it.) What can one do to rectify the situation? One should recite the Shema. (The recitation of the Shema has the ability to ward off spiritual dangers.) But if one is standing in a filthy place (not suitable for the recitation of the holy words of the Shema), one should leap four cubits from one's place. If one cannot [leap from one's place], one should say this: 'The goat at the slaughterhouse is fatter than me' (to ward off the spiritual attacker by directing it to a more tempting target)."

Rabbi Yoseph Chayim of Baghdad (a.k.a. Ben Ish Chay), in his classic commentary to the aggadic portions of the Talmud, Ben Yehoyada, explains:

"The reason [the sages of the Talmud] said one should leap, and did not say one should 'distance oneself' four cubits, is because they devised a wise [strategy] to save one from the demons (i.e. the spiritual predators) through leaping from one's place. It is known what our master, the Arizal, taught, that the entire desire of the evil inclination is to make itself appear similar to that which is holy, like a monkey vis-a-vis a man, that is, that the nature of a monkey is that it acts as the man who is before it. Therefore, the demons, who are rooted in the evil inclination, also have this nature of the monkey, to performs acts like the acts of men, in order to make themselves similar to them. Therefore, it seems that the guardian angel of this person who becomes frightened sees that there are demons standing there next to him, and if he would distance himself from that place via walking, [the demons] too would walk with him, so what good would distancing himself do? Therefore they gave him the advice to leap four cubits, for then his leaping would be great and strong according to his ability, for he would be compelled to leap with all his strength, and the demons, whose way is to mimic the action that the man performs before them, like the way of the monkey, would certainly also perform a great leaping with all their strength after seeing that this person strengthened himself to leap with all his might. Then the leaping of the demon, commensurate with its level of strength, would be to a very distant place, possibly several hours distant, for in accordance with the strength of the demon who leaps with all its strength, certainly its leaping will be a very great measure, and once it is uprooted (from its attachment to the person), it is uprooted (and will no longer follow the person). The result is that this man is separate and distant from them a great and awesome measure."

And here comes the kicker, as the Ben Yehoyada continues (emphasis added):

"And I heard people telling that a certain seaman did such a stratagem to monkeys that wore the hats that were spread out on the shore before the boat, and through such a stratagem he took all the hats that the monkeys had taken, since the nature of monkeys is to do that which the man before them does, for they desire to be similar to men."

And while Caps for Sale was published in 1938, the earliest edition of Ben Yehoyada of which I am aware was printed in 1904.