今日あって明日ない身
Meanings
1
life is transient; life is uncertain; memento mori
A set phrase expressing the impermanence of life, often used in reflective or literary contexts. It conveys that one may be here today but gone tomorrow.
Since life is uncertain, I want to live each day with care.
2
one's days are numbered; one's time is nigh
Used when someone's death is imminent or expected soon, often with a somber or fatalistic tone. More concrete than the general transience sense.
The doctor didn't say it outright, but it seems my days are numbered.