"It took me quite the while!" Amos said. "But it is no trouble, and such a pleasure, truly, to have had the task to occupy my mind."
He gestured to the obelisk. The stone was cut with ornate engravings, serpentine swirls colliding into elegant arcs. "This contraption here," the priest explained, "is cut so as to channel certain magical frequencies. With a successful Protect—" and here he cast the spell "—it ought to glow a green just like that. Anything else, and it will glow violet.
"It is best to be certain one is casting the correct spell before attempting it on oneself." The priest smiled. "We wouldn't want to do anything funny, put ourselves out of sorts, of course!"