Ray Ray

At Lifeteen mass I'll hear "ray ray nobis" in one of the songs, along with "dona nobis pacem" and can't figure out what the "ray ray" is. Googled "re re lifeteen nobis pacem" and found this:

Miserere Nobis (mize re re /nobece)- "have mercy on us"
Dona Nobis Pacem (do na/ no bece/ pa chem) "give us peace"

So I'm hearing the second and third syllables of Miserere (have mercy.) Now I can rest.