ssh exec command and exit session

[dex123]

is it possible to execute command and terminate session all in one phrase

something like this
connect to server hostname and than execute command "ls" and than some command

ssh username"at"hostname ls "something"

without "something" this phrase connects to server and lists directory, I need something that after listing directory, terminates session.

[Manko10]

It actually should terminate the session immediately after running ls. If not, just add exit:

ssh user@example.com "ls /foo/bar; exit"