The Snow-child is a widespread European folktale, found in many medieval tellings.
It is Aarne–Thompson type 1362.
The Snow-child Wikipedia
A merchant returns home after an absence of two years to find his wife with a newborn son. She explains one snowy day she swallowed a snowflake while thinking about her husband which caused her to conceive. Pretending to believe, he raises the boy with her until he takes the boy on a trip and sells him into slavery. On his return, he explains to his wife that the boy melted in the heat.
The tale appears in Medieval fabliaux, and was used in school exercises of rhetoric. It first appears in the 11th-century Cambridge Songs. A Medieval play about the Virgin Mary has characters disbelieving her story of her pregnancy citing the tale.
It contrasts to Aarne-Thompson type 703*, Snow Maiden, where a child really has a magical snow-related origin.