The phrase ‘Between a Rock and a Hard Place’ is used when in a very difficult position; facing a hard decision.
Example of Use: “I’d like to help you but I am stuck between a rock and a hard place.”
The origin of the idiom 'between a rock and a hard place' can be found in ancient Greek mythology. In Homer’s Odyssey, Odysseus must pass between Charybdis, a treacherous whirlpool, and Scylla, a horrid man-eating, cliff-dwelling monster. Ever since, saying one is stuck between a rock (the cliff) and a hard place (the whirlpool) has been a way to succinctly describe being in a dilemma.