For Luke, it was important to tell us where Jesus was “not” born. Jesus was not born in a palace, hotel, inn or even a “guest room.”

A Bethlehem house was commonly built over a cave and had only two rooms: the larger room where the family lived, cooked, and slept; the smaller room (Greek, kataluma, mistranslated in some Bible translations as “inn”), a storage room that also served as a guest room for family or friends.

Livestock were kept in the cave over which a home was built. When Joseph and Mary arrived in Bethlehem there was no room in the guest room (kataluma), so Joseph and Mary stayed in the cave with the animals and the manger.

Cultural expectations imply that when Mary and Joseph came to Bethlehem they would have gone to the home of one of Joseph’s relatives and asked to use the guest room for the night. However, due to the Roman census, other family members from out of town may have already claimed the space.

Another reason for giving birth in the cave may be found in the culture of first-century Judaism. Leviticus 12:1–4 made it clear that when a baby was born the mother became ritually unclean and her ritual impurity could make everything in the house unclean. However, the stone of the cave under the house functioned as a screen against the transmission of ritual uncleanness. Thus the decision to give birth in the stone cave may have been Mary and Joseph’s decision to prevent ritual impurity from affecting the entire house.