you're looking for how to recover deleted messages from a Samsung Galaxy phone, you can use the Trash option in the Samsung Messages app. You can also restore messages from a backup.
Restore messages from the Trash
Open the Samsung Messages app
Tap the three vertical dots to open More options
Tap Trash
Touch and hold the message you want to recover
Tap Restore or Restore all
Restore messages from a backup
Open Settings
Tap Accounts and backup
Tap Back up data under Samsung Cloud
Select the switch next to Messages
Tap Back up now
Tap Done when it's finished
Repeat the steps above, but tap Restore data instead of Back up data
