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
pāna, æ, f., Plin. Val. 3, 27, 1, c. panus.
pāna, s. panusno. II.
