What does it mean to cross the clouds?

It means walking leisurely in the clouds.

The following is an introduction to idioms:

Idioms are stereotypes in Chinese vocabulary. Idioms, everyone says they have become words, and so do idioms. Idioms are mostly four-character, and some are three-character, five-character or even more than seven-character.

Idiom is a major feature of traditional culture in China, which has a fixed structure and a fixed sentence, indicating a certain meaning. It is applied to a sentence as a whole, with subject, object, attribute and other components. A large part of idioms are passed down from ancient times and represent a story or allusion.

Some idioms are just a miniature sentence. Idiom is a ready-made word, similar to idioms and proverbs, but slightly different.

Refer to Baidu Encyclopedia-Idioms for the above information.