Guest and comrade of this my clay

Roman Emperor Hadrian according to the notoriously suspect Historia Augusta

And he is said, as he lay dying, to have composed the following lines:

O blithe little soul, thou, flitting away,
Guest and comrade of this my clay,
Whither now goest thou, to what place
Bare and ghastly and without grace?
Nor, as thy wont was, joke and play.