Who been stared at in return? Is it an allegory?
'Everything in Marseilles, and about Marseilles, had stared at the fervid sky, and been stared at in return, until a staring habit had become universal there.'
Metaphorical rather than allegorical. "Marseilles" [town and inhabitants] had stared at the sky; the sky had stared at Marseilles.
What is this from?