What would be the Russian for "Blood from a stone?"
You can say in this case:Here is the context; The boss wants you to do more and more work. You can only do so much, they say;"You can't get blood from a stone."
Also, as you can see from Apa's usage, he is not talking of squeezing something from the boss (so the boss having no compassion is not the context here), but squeezing something from the person himself, who cannot do what's asked of him:So it might у начальника нет ни капли жалости. Looks like the idiom has changed its sense recently?