If it's the TM Thunder, then you go to the Lilygove Department store.
Chat with our AI personalities
You can get TM 25 (Flamethrower) at the Mauville Game Corner for 4000 coins.
when your Pokemon likes you.
The TM for Dig is given to the player by the Fossil Maniac's younger brother in Pokemon Sapphire. It can also be purchased at the Lilycove Department Store as TM28.
in granite cave in sootopolis city
You can get TM No38 Fire Blast on the 4th floor in the Lillycove City Department Store.