Back in 2012 when the updated English translation of the mass was implemented, I was struck by the language used: it felt much more fantastical. Where previously, when the priest spoke the words of initiation, he used to say “Taking the cup, He gave thanks”, where now the priest says “Taking the chalice, He gave thanks”. To my ears, it makes the mass feel more ritualistic and something out of Lord of the Rings, which I thought was pretty cool. But the most impactful thing that was changed was the addition of a new phrase during the Eucharistic Prayer.
The phrase in particular is said when the priest lays his hands over the gifts and says “Make holy these gifts, we pray, by sending down Your spirit upon them like the dewfall.” A document from the USCCB illustrating the Jewish origins of the mass states that this phrase is an allusion to the Mana that the Israelites received every morning in the desert with the coming of the dew. Thus tying our spiritual food from heaven: Jesus, with the heavenly bread that fed the Israelites.
The phrase itself also holds deeper meaning if we look closer at the phrase itself. Dew, unlike rain, is a manifestation of moisture from the air. A quick Wikipedia search will tell us that the dew point is the temperature at which the water moisture in the air either condenses out of the air, or is absorbed by the air. If the temperature drops below the dew point, then water must be expelled from the air until a new equilibrium is reached, and the water collects on nucleation points. High in the sky, water droplets come together to form rain. But closer to the ground, the water collects on all exposed surfaces: plants, rocks, jackets you left outside while camping, etc.
Thus, the image that the phrase “like the dewfall” invokes is God’s spirit not coming down from on-high, from a distant and detached position above the world. Rather, God’s spirit is made manifest from all around us, constantly enveloping and filling us. I think it’s a nice reminder that God isn’t distant and cold, looking down upon His creation, but instead He is always around us and with us.
 Pitre, Brant. “The Jewish Roots of the Mass.” Catechetical Sunday 18 September 2011. Web.