Example in Pro Bash Programming book problem

I am going through the examples in the book "Pro Bash Programing" which is quite a good book on bash programing. Just a word of warning about the example script called sa that simply shows command line arguments. In CentOS 5.5 there is a program called sa already on the system. Boy did that throw me off for awhile. Everything works using the dot slash ./sa {1..10} but bombs when using just sa {1..10}. It took me a half hour scratching my head why this wasn't working when everything was working fine the previous half hour.

#!/bin/bash
## script name: sa
## Purpose: Displaying Command-Line Arguments
pre=:
post=:
printf "$pre%s$post\n" $@

Error that I was getting:
$ sa {1,2,3}
sa: extra arguments `1', `2', `3' -- aborting

Correct output example:

 
$ ./sa {1,2,3}
:1:
:2:
:3:

So does anybody know what the redhat sa command is for? I looked at the man page but can't make any sense out of it. Running it doesn't create any output to the screen.