“You cannot kickstart a dead horse”

Jacula Prudentum (1651)

Act I, scene II. — (Polinico).
Translation reported in Harbottle's Dictionary of quotations French and Italian (1904), p. 241.
La Calandria (c. 1507)

The Fantastic Imagination (1893)
Context: "But surely you would explain your idea to one who asked you?"
I say again, if I cannot draw a horse, I will not write THIS IS A HORSE under what I foolishly meant for one. Any key to a work of imagination would be nearly, if not quite, as absurd. The tale is there, not to hide, but to show: if it show nothing at your window, do not open your door to it; leave it out in the cold. To ask me to explain, is to say, "Roses! Boil them, or we won't have them!" My tales may not be roses, but I will not boil them.
So long as I think my dog can bark, I will not sit up to bark for him.

Source: Translations, Monkey: Folk Novel of China (1942), Ch. 27 (p. 266)

The Horses of Achilles http://www.cavafy.com/poems/content.asp?id=134&cat=1
Collected Poems (1992)
Context: When they saw Patroklos dead
— so brave and strong, so young —
the horses of Achilles began to weep;
their immortal nature was upset deeply
by this work of death they had to look at.