Recover pending text messages deleted before sent
It is extremely unlikely that you can recover the text message itself, but you can try following something like this.

If you haven't rebooted your phone, you could also try running this from your PC while your phone is connected:

adb shell "logcat | grep handleSmsReceived"


The output will look like:

D/Mms/Txn ( 9092): handleSmsReceived messageUri: content://sms/789, address: +15551234567, body: this is a text message


If you don't have ADB installed, you can get it from the Android SDK Tools.