The characters literally combine to paint a picture: “in an emergency (急), to come (来) and hug (抱) the Buddha's (佛) feet (脚).” This visual metaphor is so strong that its meaning—a desperate, last-minute action born from a lack of foresight—is immediately clear.
This idiom underscores a cultural emphasis on being prepared and views last-minute panic as a character flaw rather than just a time-management issue.