Question

That's the source of blue sky I like to see
Is it a metaphor or simile​

Answer 1

Explanation:

This is called a simile, because it's similar. ... If you wanted to describe the sky in your poem you might use an adjective - blue sky (boring), brilliant blue sky (still quite boring) - or you might use a simile: The sky was as blue as a millionaire's swimming pool (not boring at all, and very descriptive).