Liturgical Words as a Private Prayer?

[Lady Grey, Hot]

Sometimes as I pass an adoration chapel the words that spring to my mind are "May the Body of Christ keep me safe for eternal life." Since these words are only spoken by the priest within the context of the Mass, is it wrong for me, a layperson, to use them as a private prayer? For that matter, would there be anything wrong with a layperson saying the phrase to themselves as they go up to receive?

[Luigi]

There is nothing wrong with praying - any words, any time. You can pray the joyful mysteries on a Friday, and the sorrowful mysteries on a Sunday if you want to. That is, as long as you're not being sacrilegious; in other words, you can't try to transubstantiate bread and wine in your own home. (But I don't think those words are really a prayer, anyway - I think they'd be classified as performative speech acts.) The Vatican doesn't copyright the words of prayers, nor do the people who write them (Thomas Aquinas, Teresa of Avila, et alia). This "certain prayers at certain times" approach was mostly a way to help the laity develop patterns of praying. But none of that is carved in stone. 

So pray with wild abandon! 

Edited June 20, 2021 by Luigi

[chrysostom]

What Luigi said.

Regarding the specific words of the prayer you thought of, that's a beautiful prayer. In the old Mass the priest says to the communicant while distributing Communion: Corpus Domini Nostri Iesu Christi custodiat animam tuam in vitam aeternam, Amen. Which in English means “May the Body of our Lord Jesus Christ preserve your soul unto life everlasting. Amen.” So it is a great thing to turn around and put that prayer into the first person.