Notes:

dA source

Translation:
"Eternally Clear Sky, Not a Blight in Sight"

Supposedly comes from some Korean poem, but I don't know exact source.

EDIT:
The Korean poem in question is "Who Said He Watched the Sky" (누가 하늘을 보았다 하는가) by 신동엽 (Dong-Yup Shin)

Here is the full poem in Korean.