@crun ok I could seperate the phone number with dbus service org.ofono.MessageManager. Listening on signal IncomingMessage (service: org.ofono, path: /ril_0, interface: org.ofono.MessageManager). There you get a variant map [string, variant]. The second key is "Sender" where its variant holds the number.

I attach a deb which I used for listening on ImmediateMessage, IncomingMessage and MessageAdded. But for me only IncomingMessage got triggerd. It has some debug messages and in the end it prints to stdout the number. You can quit with x+enter.

EDIT: lol wrong slot, IncomingMessage got triggerd not Immediate, fixed it.