odd error from bash exec binary on cmd line

[L A Walsh]

Using bash-4.4.12...

If I use bash -c, I get a variety of correct messages:

>  bash -c xxx
bash: xxx: command not found

>  touch xx
Ishtar:law/bin> bash -c xx
bash: ./xx: Permission denied

or when it works, it just does:
bash -c "sleep 1"
(sleeps 1)

but if I leave off the '-c', like:

bash sleep 1

I get:

/usr/bin/sleep: /usr/bin/sleep: cannot execute binary file

???
Isn't it bash that cannot execute the binary file because
it expected a script?

Shouldn't bash be to the left of the ':' with some
error on the right, like "cannot exec binary file" or
"expected script file"?