The problem for the Medieval Spanish scholars who were tasked with translating this material is that the letter sheen and the word shayun can't be rendered into Spanish because Spanish doesn't have that SH, that "sh" sound.
El problema dels erudits de l'Espanya medieval que van haver de traduir aquest material és que la lletra "xīn" i la paraula "xalan" no es poden traduir a l'espanyol, perquè l'espanyol no té la "sh", el so "sh".