When he said "meditation," I had the impression he was about to say "prayer" but changed it. Just an impression... a slight delay before he used the word.
Maybe he was about to say "climax," who knows fer shore? :D
There isn't enough data to see if there's a regular time for this, the few times he's reacted seem to be random. I ain't about to experiment and make dishwashing noises throughout the day just to see if it ticks him off at any particular times.
If I knew what times he "meditated," or "prayed," or whatever, I'd accommodate him to the extent of not running water at that time just out of respect. Just like I don't flush the toilet in the middle of the night so as to not disturb my downstairs neighbors.