You said you want to copy data using rsync but the command introduces much ambiguity. Where are you trying to copy to?

The -e 'ssh' indicates that you are trying to initiate a remote connection using the ssh protocol but no host name is given, nor the arrangement of source and destination is like given.
The -a (archive) flag is a combination of many others, including -r (recursive), therefore is not necessary to have by itself.

The -z is for compression on the transmission, arguably not necessary when doing a local copy.

If we remove the -e 'ssh' we end up with a copy of a whole directory (dir) from local source to local directory (singh_directory) destination, which it has its own problems as stand. dir lives already in singh_directory.


When using / at the end of source, rsync will copy the content of the last directory.
Not using / at the end of source, rsync will copy the last directory and the content of it.

When using / at the end of destination, rsync will transfer the data inside the last directory.
Not using / at the end of destination, rsync will create a directory with the last destination name and will transfer the data inside that directory.