another way to say the same thing.

also, in the "don't count your chickens before... " the term chicken is usually plural

I found this context with a simple google. https://books.google.sc/books?id=3D5_Q-lUYioC&pg=PT144&lpg=P...
It is an interview of a band:
"Siete autori di una compilation 'Salento Showcase' … . Avete qualche nome da publicizzare?"
"Ancora è presto per fare nomi … anche se un paio mi andrebbe di farli, ma *mai promettere il sole prima che sorga*”
This looks like a proverb, but it is not one I know and googling the phrase turns up nothing except this interview. In the context the meaning is clear, never promise a name or anything until it has actually happened, until you have decided the name, until you can see it in the sky. But why translate with an explanation when you can just translate literally with no problems whatsoever.