A roc is a mythical giant bird. Though in this case it is the Chinese "peng" which apparently is somewhat different:noba said:Thank you!
Re: idiom
"the fabled roc flies ten thousand miles" (idiom) / (one's future prospects are brilliant)
What is a "roc"?Click to expand...
Peng (mythology) - Wikipedia, the free encyclopedia
Now the excerpt on the wikipedia page may give a clue to the first line on the scroll:
"The back of the P'eng measures I don't know how many thousand li across and, when he rises up and flies off, his wings are like clouds all over the sky."
The three characters that we are sure of are 雲 cloud 展 spread 翼 wing
But I must disclaim I only know basic Chinese and I suggest if you need an accurate translation you would be better off asking on a Chinese forum (I don't believe we have any fluent speakers here).