hand to mouth, from

(from) hand to mouth

With just the bare minimum of money, food, or resources to survive, with little or nothing else to spare. Usually preceded by "live." It's been pretty hand to mouth these days. If I don't find work soon, I don't know how we'll get by. With another child on the way, it looks like we'll be living from hand to mouth for the foreseeable future.
See also: hand, mouth
Farlex Dictionary of Idioms.

hand to mouth, from

With only the bare essentials, existing precariously. For example, After she lost her job she was living from hand to mouth. This expression alludes to eating immediately whatever is at hand. [c. 1500]
See also: hand
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • hand to mouth
  • (from) hand to mouth
  • the dust settles
  • hang a BA
  • hang a BA (at someone)
  • hang a BA at someone
  • Ba
  • one's fair share
  • your fair share of something
  • (one's) fair share (of something)
References in classic literature
At eighteen he would have dragged on from hand to mouth, from hour to hour, from penny to penny, until eighty.
Gill Ford, vice chairman of legal redress for the Denver chapter of the NAACP said to the Denver Post, "How many of the poorest families, those living hand to mouth, from paycheck to paycheck, are likely to have $2,500 extra to just set out there for tuition?