The Donkey That Learned Not to Eat

Easy Greek Reader by Evelyn Abbott. Internet Archive link. There are notes for the stories (this is story 16 in the section called "Wisdom of Fools"), and a vocabulary in the back of the book. In addition to the Wisdom of Fools, the book features Aesop's fables and stories from the Life of Aesop.

Σχολαστικός θέλων τὸν ὄνον αὐτοῦ διδάξαι μὴ τρώγειν, οὐ παρέβαλεν αὐτῷ τροφάς. ἀποθανόντος δὲ τοῦ ὄνου ἀπὸ λιμοῦ, ἔλεγε· "μεγάλα ἐζημιώθην· ὅτε γὰρ ἔμαθε μὴ τρώγειν, τότε ἀπέθανεν."

Σχολαστικός
θέλων διδάξαι
τὸν ὄνον αὐτοῦ 
μὴ τρώγειν,
οὐ παρέβαλεν αὐτῷ
τροφάς.

ἀποθανόντος δὲ τοῦ ὄνου
ἀπὸ λιμοῦ,
ἔλεγε·

"μεγάλα ἐζημιώθην·
ὅτε γὰρ
ἔμαθε μὴ τρώγειν,
τότε ἀπέθανεν."

"Scholasticus" (the fool)

Σχολαστικός 

wanted to teach his donkey

not to eat

θέλων 

τὸν ὄνον αὐτοῦ διδάξαι

μὴ τρώγειν 

and did not give him

 fodder

οὐ παρέβαλεν αὐτῷ 

τροφάς. 

when the donkey died

from hunger

ἀποθανόντος δὲ τοῦ ὄνου

ἀπὸ λιμοῦ 

the fool said

ἔλεγε 

"I've suffered a great loss!"

μεγάλα ἐζημιώθην· 

for just when he learned

how to not eat

ὅτε γὰρ ἔμαθε μὴ τρώγειν 

he died

τότε ἀπέθανεν."