WP-CLI provides an easy shortcut for accessing specific database tables where your content. Using the command below you can have WP-CLI go into the database, get post content, and output that content to a file:
Send content to a file in the same directory:
$ wp post get 123 --field=content > file.html
Second content to a file in your home directory by adding a tilde ~
:
$ wp post get 123 --field=content > ~/file.html