You cant get the actual message but you can see who, what number, time etc by doing the following
Detail Request for send and receive, phone number or email address] and date/time
Customer wants a copy of the texted numbers not the content of the text messages.
Sprint sends a form in 7-10 days to the account holder or a business’ authorized contact (as identified in CSM) which they must notarize and return within 14 calendar days. Cases are closed if not received within 14 days.
Upon receipt of the notarized form, Sprint provides text messaging detail only via postal mail within 7-10 days. Detail is limited to the previous 90 days.