You cannot reliably see the original content of a WhatsApp message after it has been deleted for everyone
Check your notification history if it was enabled before the message was deleted
Review any chat backup made before the deletion, then restore that backup to view the message
Ask the sender to resend the message
Check if the message was quoted or forwarded in another chat
On Android, some third-party notification log apps may have recorded the message if installed beforehand
On iPhone, use available notification previews if they were visible before deletion
If the message was deleted before you saw it and no backup or notification record exists, it cannot be recovered through WhatsApp itself