The Mosaic and Window Puzzle

In its present form, this puzzle works best in a (pseudo)Christian setting, but it could easily be adapted to other settings given the appropriate information.

I ran it to find the lost grave of a saint in a monastery. The patron had indicated that the grave was in a specific location. Arriving, the party found a stained glass window at one end of the scriptorium with an almost identical mosaic at the opposite end:

An innocuous bible reference points to a specific verse, which reads “That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked at and our hands have touched—this we proclaim concerning the Word of life.”

Investigating the mosaic reveals that certain stones can be depressed, namely some on the ears (‘heard’), eyes (‘seen’), hands (‘touched’)and lips (‘proclaim’). Pressing all of these together opens up a secret compartment holding the saint’s bones.