I’ve been curious about this for a while but it never dawned on me to ask. I finally did ask my priest and he’s not sure of how or why this practice started.
I’m referring to the “sharing” of holy water between members of a procession coming into a church. Anyone who’s been an altar server likely knows what I’m talking about: where the first person in the procession (usually but not always a crucifer) dips his fingers into the holy water font upon entering and then turns around and touches the hand of the person behind him before signing himself with the cross. The person behind him then turns to the person behind him and does the same before signing himself. This continues onward until the last server/acolyte/seminarian/deacon/whatever finally touches the hand of the priest.
What’s the significance of this and how did it arise? Why doesn’t each and every individual dip their own fingers into the holy water font upon entering?