When leaving the land of the dead, the burning city, the doomed house: do not look back. A taboo attested from Greece to Korea to Gabon, with no obvious author.
Documented
The family is catalogued
The comparative catalog is real scholarship: Jan Bremmer's essay Don't Look Back: From the Wife of Lot to Orpheus and Eurydice (in Sodom's Sin, Brill, 2004, reprinted in his 2008 collected studies) traces the shared structure across Greek and Hebrew sources. The Stith Thompson Motif-Index files the rule under C331, tabu: looking back, and its etiological branch under attestations like A2332.3.1, the Fang tale where the lemur looks where forbidden and gets his huge eyes, collected by Nassau in West Africa in 1912. Korea's Jangja pond and the Pythagorean symbola belong to the same family.
Assessment: Fully documented as a motif family. The catalog proves distribution, not descent: nobody has shown a chain of custody from Sodom to Korea, and the honest filing is independent invention until proven otherwise.
Stories
Two names carry the whole rule
Ask anyone to name the rule's victims and the same two come back: Orpheus, who looked at Eurydice, and Lot's wife, who looked at Sodom. The folk reading makes the motif a proverb against nostalgia: the past is a city on fire, and turning to watch it burns you too. Self-help books and breakup songs run on it to this day.
Assessment: Stories: the proverb reading is real usage, but it flattens the texts. In both headliner stories the looker is not weak but attached, which is a different diagnosis and a darker one.
Interesting claims
The look is a border violation
The boundary reading: the glance is never curiosity, it is jurisdiction. The one who looks back tries to hold two worlds at once, and the rule exists to keep the worlds priced apart: the dead stay dead, the city stays burned, the past stays past. The punishment is the border reasserting itself. Note what follows: the rule does not protect travelers from harm, it protects separations from travelers. Every version agrees the look is fatal. None agrees on why.
Assessment: Interesting: it explains the family's shape, the underworld, the condemned city, the sunken house, better than the nostalgia proverb does. What it cannot explain is why the boundary needs a loophole at all. If the look truly undid nothing, there would be no rule against it.
Sources and further reading
Bremmer, Don't Look Back: From the Wife of Lot to Orpheus and Eurydice, in Sodom's Sin (Brill, 2004), reprinted in Greek Religion and Culture, the Bible and the Ancient Near East (2008)
Stith Thompson, Motif-Index of Folk-Literature, C331 tabu: looking back; A2332.3.1 the lemur's forbidden look (Fang, per Nassau)
Nassau, Where Animals Talk: West African Folk Lore Tales (1912), the Shrew and Lemur etiological tale
the Encyclopedia of Korean Folk Culture, Jangja-mot entry
Diogenes Laertius 8.17, the Pythagorean symbolon
Worth asking
If the rule exists to protect the traveler, why does it only ever punish the merciful and the in love?