You cannot prevent commands from sending status messages, but you can prevent the status messages from being displayed at the bottom of the screen.
There are two preferred ways to prevent the status messages from being shown:
You can change your user profile so that whenever you sign on using that profile, status messages are not shown. To do this, use the CHGUSRPRF command and specify *NOSTSMSG on the User Option (USROPT) parameter.
You can change the job you are currently running so that status messages are not shown. To do this, use the CHGJOB command and specify *NONE on the Status Message (STSMSG) parameter. You can also use the CHGJOB command to see status messages by specifying *NORMAL on the STSMSG parameter.
A third alternative, however less preferred, is to use the Override Message File (OVRMSGF) command and change the status message identifiers to a blank message.