"did "chmod 0600" now."
You just made it read+writable by just you - you're running ssh by you, right?
I referred to the man page because I thought there would be something I could just quote and learned something "Omitted digits are assumed to be leading
zeros." which makes sense, as I intuitively knew if I left out the sticky bit, it would be unset but always thought: user, group, everyone else. So, 'chmod 0 config' doesn't look as cluttered and conveys the same meaning :)