Note that below SQL gets output if it is still in UNDO tablespace.
SQL>
SELECT text FROM all_source
AS OF TIMESTAMP TO_TIMESTAMP ('21-04-2017 14:30:00', 'DD-MM-YYYY HH24:MI:SS')
WHERE name = 'PRG_BODY_ALPER'
AND TYPE = 'PACKAGE BODY';
for DBA: dba_source table
Related: https://ozsoyler.blogspot.com/2016/12/how-to-rollback-committed-data-from.html
SQL>
SELECT text FROM all_source
AS OF TIMESTAMP TO_TIMESTAMP ('21-04-2017 14:30:00', 'DD-MM-YYYY HH24:MI:SS')
WHERE name = 'PRG_BODY_ALPER'
AND TYPE = 'PACKAGE BODY';
for DBA: dba_source table
Related: https://ozsoyler.blogspot.com/2016/12/how-to-rollback-committed-data-from.html