οὐκ ἂν λάβοις παρὰ τοῦ μὴ ἔχοντος → you can't take from one who doesn't have, you can't squeeze blood out of a turnip, you can't get blood out of a turnip, you can't get blood from a stone, you can't get blood out of a stone
canal: P. διῶρυξ, ὁ, διόρυγμα, τό.
pipe: P. αὐλών, ὁ, Ar. ὑδρορρόα, ἡ.
