Virgil refers to the medieval belief that God adorned Cain's head with thorns and exiled him to the moon for having murdered his brother Abel. Cain became, therefore, a kind of medieval "man on the moon."

Virgil reminds Dante of the full moon which had aided him with its light when he was lost in the selva oscura, the dark wood, in Canto 1.

Virgil is pointing to a group of witches. They are characterized as women who abandoned the proper work of women (in the perspective of the 13th century), weaving, to become soothsayers and magicians.

Asdente, which means toothless, refers to Benvenuto of Parma, a shoemaker and prophet whose prophecies seem to have been often accurate. He successfully predicted, for example, the defeat in 1248 of Frederick II at Parma.

Guido Bonatti (1210–1296) was the premier astrologer of the 13th century. He served as court astrologer of several political leaders, including Frederick II, Guido Novello de Polenta, and Guido da Montefeltro. As a supporter of the Ghibellines, Dante's political enemies, Bonatti claimed that the key Ghibelline victory at Montaperti resulted in part from his astrological calculations.

Michael Scot (1175–1232 CE) was a Scottish scholar, astrologer, and alchemist widely known across Europe in the Middle Ages. He published commentaries on Aristotle and Averroes and served as court astrologer for Emperor Frederick II. According to legend, Scot predicted that he would die from being struck on the head by a rock. From then on he wore an iron skullcap to mitigate the coming calamity. One Sunday while he was in church, Scot removed his cap out of respect for liturgical tradition. A stone tumbled from the cathedral's roof, fell directly on Scot's head, and, killed him, fulfilling his prophecy.

Eurypilus is character in Virgil's Aenied. He was a Greek soldier who went to Apollo's temple to determine when the Greeks should sail back to Greece at the conclusion of the Trojan War. Here, however, Dante categorizes him as a prophet, indicating that Dante may have misunderstood, or misremembered, his role in the Aenied, or that he chose to tell Eurypilus's story in a new way.

At the dawn of the Trojan War, Calchas was the Greek prophet who determined when the Greek fleet should cut its cables at Aulis and sail for Troy.

Aulis was an Ancient Greek city, corresponding to modern-day Avlida. It was the embarcation point of the Greek fleet on its way to Troy to begin the Trojan War.

Virgil wants his version of Mantua's founding and history to be considered the only true version, primarily because it denies the mythical connection to the pagan soothsayer Manto.

Virgil refers here to the Guelph political leader of Mantua, Alberto de Casalodi (1320–1288 CE). In 1272, Ghibelline leader Pinamonte de Bonaccorsi convinced Casalodi to surrender Mantua to the Ghibellines. Dante, a Guelph, refers to Casalodi's actions as "madness" and Bonaccorsi's as "deceit."

Virgil wants to emphasize the fact that the city's founders did not engage in any divination in the establishing of the city.

It seems important to Virgil that everyone understand that Manto, the founder of Mantua, was in the area before it had any permanent inhabitants. Because this "pouch" of the underworld punishes false prophets like Manto, Virgil does not want to connect the city close to his birthplace with Manto, and so on the timeline of Mantuan history, he places her before the city's founding.

That is, when the stream begins to flow it is called Mincio, rather than Benaco (the lake that serves as its source water), until it reaches Governo (Governolo), where it joins the Po River.

Peschiera—Italian for "fish pond"—is a fortress that stands against the Brescians and Bergamesques where the shore is most exposed by the lake.

Virgil refers to the bishops of Verona, Brescia and Trento, whom he characterizes as shepherds of their various flocks.

"Benacus" is a reference to Benaco, also known as Lake Garda, where Manto is thought to have founded Mantua.

Manto is the daughter of Tiresias and, like her father, can see future events. After Tiresias's death, she traveled to Italy and, according to legend, founded the Tuscan city of Mantua. This event is important to Virgil because he was born in a village near Mantua.

This refers to the region of Carrara in northern Italy—Tuscany, to be specific. Carrara is known for producing very pure white marble. 

Aruns is an Etruscan prophet who foretold the disastrous Roman Civil War between Caesar and Pompey.

Next, Virgil points out Tiresias, a prophet from Thebes who spent part of his life as a woman as a punishment for having struck the female of a pair of snakes. Seven years later, he struck the same two snakes again and was changed back into a man. Eventually, Jupiter (Zeus) and Juno (Hera) asked him whether a man or woman enjoys the act of love more, and Tiresias supported Zeus's view that women get more pleasure from lovemaking. Juno in anger then blinded him, and Jupiter, to compensate for his blindness, granted him the power of prophecy.

When Amphiaraus was swallowed by the earth, he fell deep enough into the Underworld to reach one of the three judges, Minos, who determines sinners' punishments.

Virgil refers to Amphiaraus, a prophet from Argos, who was persuaded by his wife, Eriphyle, to join the expedition against Thebes, known in Greek mythology as "The Seven Against Thebes" (so named for the seven kings who led the army). Amphiaraus, who foresaw that none of the seven except Adrastus would survive, knew he was doomed, so he asked his son to avenge his death by killing Eriphyle should he not return. During the retreat from Thebes, Amphiaraus was swallowed by the earth and fell into the underworld.

Virgil, who holds no sympathy for these sinners, rebukes Dante for his feelings of pity.

In one of the occasions in which Dante breaks the fourth wall and addresses readers directly, he expresses the hope that God might allow readers to fully understand what they have read. Dante makes such direct addresses to draw readers more deeply into the narrative.

Dante suggests that palsy (a disease of the nerves) may have forced some prisoners to walk backwards.

Reins is an archaic word for the area of the heart and stomach, which was thought to be the area of the body in which passion and emotion originates.

The prisoners walk as slowly as those walking in religious processions. This is ironic, given the sacrilegious nature of their offenses.

Virgil and Dante have reached the Fourth "Pouch" of the Eighth Circle, in which those who claim to know God's intentions, as well as magicians and astrologers, are punished by having their heads turned backwards.