If the Salaam is Delayed in Error?

Q: Salaah-33: I did not make Salaam after reciting Tashahhud, Durood and the Du'aa in the final sitting (Qa'dah Akheera). I realised this only after sitting awhile and then immediately made the Salaam. I however did nothing in between that nullifies the salaah. Is my salaah valid or does it need to be repeated?

Answer: You needed to perform Sajdah Sahw in this case. Had you done so, the salaah would have been valid. If not, it will have to be repeated. And Allaah knows best what is most correct.

Fatawa Rahimiyyah vol.2