What the strong men of Titan mean by repetition is any sequence of sounds that immediately follows the same sequence… so
is not a sinful utterance because of this:
but is a sinful utterance because of this:
Show that the strong men of Titan make 10 sounds in a row without sinning?
Extensions:
When the evil Strong Men of Titan want to sing an evil chant, they write X utterances on a wheel and whirl it around and around - singing as it spins. Is it possible that they don't sin until they have spun the wheel twice?
The answer is yes for the following wheel of 4 utterances:

Find a larger wheel for which this is true?
Whenever the Strong Men of Titan drive on their orthogonal highways, they never repeat a sequence of turns. Replace "B,U,K" above with "Forward, Left, Right" to get an idea of how they move. After he begins his journey by moving forward, can a Strong Men of Titan ever return home to his mom?

An example of a strong man trying to return
home to mom (red dot) without sinning.
What is the largest N by M paragraph (N,M >1) so that no two rectangles sharing an edge have a repetition? The following 6x6 paragraph is sinful because the red rectangles repeat: