Sha Wujing's "Liu Li Sin" is not a story about learning from scriptures, but a long confession of a sinner who walked for fourteen years carrying the evidence of his crime.
When Monk Tang received the scriptures at Leiyin Temple, the burden that Sha Monk put down revealed the real "scriptures" on the way to the scriptures - nine skeletons that turned into lotus flowers, and a side of broken glass that reflected the sins of everyone's previous lives.
This is a story about how silence can be deafening. While Wukong was fighting, Bajie was complaining, and Tang Monk was chanting, Sha Monk was carrying their secrets, heaven's conspiracy, Buddhism's calculations, and the whispers of nine forgotten souls through the eighty-one difficulties.
He may be the most sane person on the journey west, or he may be the craziest. Because only he knew: those they escorted had already been killed by them.