Have your iPhone read out your texts
If you require or want your iPhone to read out your texts, then you can enable Speak Selection.
First of all navigate to Settings > General > Accessibility and toggle the option 'Speak Selection'.
If you are to long-press on a speech bubble within your Messages, you'll now find the option to 'Speak' - the option is especially useful if you have a long text message or decide to start driving and want to listen to the text whilst in hands-free mode