welcome rain in a drought; timely relief
A yojijukugo literally meaning 'merciful rain under a drought sky'; used figuratively for any long-awaited help or relief.
After a long drought, welcome rain finally poured down.
His support was truly a welcome relief.
慈雨 alone means 'welcome rain' or 'blessed rain', but 旱天慈雨 emphasizes the contrast with drought and is more often used figuratively.
恵みの雨 is a common expression for 'blessed rain', while 旱天慈雨 is a literary yojijukugo with a stronger figurative sense of relief.
A yojijukugo composed of 旱天 (drought sky) and 慈雨 (merciful rain). The exact origin is uncertain, but it follows a classical Chinese-derived pattern of four-character idioms.