Making the Sajdah Sahw after Both Salaams

Q: Salaah-145: A person forgot to make Sajdah Sahw and remembered only after making both Salaams. He then performed the Sajdah Sahw and completed the salaah by repeating the At Tahiyyaat, Durood and du'aa. Will the salaah be valid or is it necessary to repeat it?

Answer: The salaah will be valid in the stated case and need not be repeated.

Fatawa Rahimiyyah vol.2