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
P. and V. ἀπορρεῖν, V. κηκίειν; see spurt.
Met., declaim: Ar. and P. ῥαψῳδεῖν (acc. or absol.).
nozzle: use P. τὸ προέχον.