Basic explanation
This year I ate the grain of the second year. Metaphor is economic difficulties, income is not enough to spend, and future investment is spent in advance. Metaphor economic difficulties, make ends meet.
derogatory sense
tidy
Qing Li Garbo's "Officialdom" (15): "How much will it cost to eat only one ration?" Even the general manager of our small business is short of food first and then empty. "