Help understanding a song
I'm trying to understand the song "간양록" by 조용필, but the grammar is hard to understand.
"이국땅 삼경이면 밤마다 찬서리고
어버이 한숨쉬는 새벽달일세
마음은 바람따라 고향으로 가는데
선영 뒷산에 잡초는 누가 뜯으리
피눈물로 한줄한줄 간양록을 적으니
님 그린 뜻 바다되어 하늘에 닿을 세라"
The most confusing parts are:
"찬서리고." This means "찬 서리이고," right? If I understand correctly, that means "is cold frost." What is the thing that is cold frost? Is it saying "there is cold frost"?
"어버이 한숨쉬는 새벽달일세." Does this mean "The waning moon is my parents sighing"?
"님 그린 뜻 바다되어 하늘에 닿을 세라." Is "님 그린 뜻" the same as "님을 그린 뜻에서"? Is he saying he is afraid his tears will reach the sky?
Thank you for your help!