Where in the GIRM is a EMHC allowed to bless people who are not receiving but cross their arms for a blessing. Or is such a permission granted in another document?
There is nothing in the GIRM or any liturgical document that calls for the EMHC to bless anyone at any time during the Mass.
However, situations can sometimes be forced upon us and we might not want to embarrass someone or cause a scene at the moment since individuals who present themselves for blessings at communion time usually do so with the best of intentions and thinking that it is perfectly fine. In such situations it may be more prudent to simply say “God bless you” to the individual and continue distributing communion to the next person.
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