παρεγγύη
From LSJ
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
English (LSJ)
ἡ,
A command, X.An.6.5.13. 2 = allegatio, insinuatio, Gloss. II Dor. παρεγγύα, deposit paid by a contractor, IG42(1).109 ii 152 (Epid., iii B. C.).