Q. Is the tradition referring to Christ’s birth in a "manger" based on the Biblical account?
A. Yes; St. Luke’s Infancy Narrative explicitly states that the newborn Christ Child was wrapped in swaddling clothes and placed in a manger. The Greek word for "manger" used by St. Luke is φάτνη (transliterated, phatne), meaning "manger," "feeding-trough" or "stable." (Lk 2:7). The text reads, "She [Mary] wrapped him in swaddling clothes and laid him in a manger…." (NAB)
The Greek for "manger" can also be rendered as "stall" or "feeding place." However, the usual and almost universal translation of the scene at Christ’s birth is "manger." It is a word that Luke repeats a total of four times in his Christmas story. For example, the "manger" is cited by the Christmas Angel in the message to the shepherds: "For today …a Savior has been born for you… you will find an infant wrapped in swaddling clothes and lying in a manager…." (Lk 2:12)
Interestingly, Luke’s reference to the manger in his Christmas narrative is especially significant because of its "sign" value. Biblical scholars point to the prophecy of Isaiah 1:3: "An ox knows its owner,/ and an ass, its master’s manger;/ But Israel does not know,/ my people has not understood…."
This text indicates that the shepherds’ enthusiasm should be seen as in contrast with Israel’s nonchalance, indeed, nonconcern, regarding the Savior’s Nativity.
Reference to a "manger," given the real-life situation then (the German phrase is Sitz in Leben), would most certainly be part of a grotto or a small cave dug out of a hillside. (Was it a cave once used to safeguard King David’s horses?)
St. Justin Martyr (d. 165), a native of the area, recounted that Joseph, without a place to lodge in the village, cleared out one of the caves near the village. Origen reflects this same narrative at the beginning of the third century.
While discussing the manger of Jesus’ birth, it is important also to analyze the significance of the "swaddling clothes." (Luke 2:7 and 12) Curiously, these wrappings constitute a portion of the "sign" of the manager. The Greek used by Luke appears only here in his Gospel and contrasts with an Old Testament text of Ezekiel, in which the absence of such wrappings is mentioned as a "sign" of maternal abandonment. See The Truth of Christmas, Beyond the Myths, René Laurentin; trans. Michael J. Wrenn, 1986.
In the above-cited volume, Luke 2:7 ("She wrapped him in swaddling clothes….") is compared with Luke 23:53, the story of Jesus’ burial: "And he wrapped [it] in a linen shroud and laid him in a tomb…."
An added note about the Cave of Jesus’ birth: Origen informs us that the Cave was venerated as early as his time (third century). In a famous work call Contra Celsum, he added, "What is shown there is famous … even among people alien to the faith."
For more details on the manger and the cave, see The Truth of Christmas, cited above. Currently, of course, we all are awaiting a new monograph by Pope Benedict XVI, who plans to add it to his two-volume Jesus of Nazareth series.