Saint Louis IX of France by El Greco
During the Nicene Creed on Sundays and Holy Days, we Catholics make a reverence at the words:
"He became incarnate from the Virgin Mary, and was made man."
Those using the the current Roman missal make a profound bow when reciting these words. In the Latin Mass, Catholics genuflect when they recite these words in order to show reverence to the mystery of the incarnation.
Where did this custom of reverencing during the Creed come from?
The answer lies with today's saint - Saint Louis IX the King of France. In his private chapel, Saint Louis would genuflect during the Nicene Creed to show reverence to the incarnation of Christ. During the crusades, the king's practice became widespread and eventually part of the rubrics of Holy Mother Church.
An interesting liturgical fact on this feast of Saint Louis IX.
Saint Louis pray for us.