How to echo sql statements in sqlplus

I am using Oracle 9.2.0.5 on HP UNIX 11i

I have a shell script:

sqlplus << !
set echo on;
set feedback on;

select * from tab1;
select * from tab2;
select * from tab3;

I want statements such as select to be shown in addition to returned data from the select's. I thought that is purpose of set echo on. I do not see any difference in
set echo on;

or

set echo of; Received on Sun Dec 11 2005 - 20:19:02 CST