Sajda-e-Sahw

Remembering to make sajdah sahw while reciting Durood-e-Ebrahim

Q: When sajda-e-sahw is to be done, the procedure is that it will be performed in the last qa'dah, i.e. after tashahhud, one salam to right and then 2 sujood. Sometimes due to carelessness I recite part of durood after tashahhud and then realize that I have to do sajda-e-sahw then what should I do at that moment? Should I proceed to sajda-e-sahw at that moment?

Forgetting to make sajda-e-sahw

Q: I forgot to perform sajdah sahw which was wajib upon me during the first 4 rakats of sunnah namaz. Then I started Fardh namaz and once I finished fardh namaz I realised that I forgot to perform sajdah sahw for sunnat namaz. Is it permissible to perform the missed sajdah sahw of the sunnat namaz after the fardh prayer?