Question: Why can’t Holy Water be sold? You may have noticed that Holy Water bottles and similar items for sale, always include a notice: “Holy Water Not Included”.
Answer: The selling of spiritual goods such as blessings or sacraments is called "simony." (Named after Simon the Magician in Acts 8:18-20). Spiritual goods are gifts from God that are sacred and not to be profaned or reduced to simple objects that can be bought and sold.
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https://www.catholiccompany.com/getfed/why-cant-holy-water-be-sold/