I do not know what year it was that they got wind of the Tang court in the east dispatching a monk to the Western Heaven to fetch scriptures — they say this Tang Monk is a good man of ten incarnations of self-cultivation, and that anyone who eats a piece of his flesh will have his years lengthened and live long without growing old.

差 is chāi, to dispatch on duty, a different word from the chà ten units back. 十世修行 is ten lifetimes of practice, the pedigree that makes the flesh worth eating. And 長生 takes 長 as cháng — long life, sealed four times that way in earlier chapters, never as the zhǎng of growing.