(172) باب مَا جَاءَ فِي سَجْدَتَىِ السَّهْوِ بَعْدَ السَّلاَمِ وَالْكَلاَمِ .
Abdullah bin Masud narrated:
"The Prophet (S) prayed five (Rakah) for Zuhr, so it was said to him: 'Has the prayer been added to, or have you merely forgotten?' So he (S) performed two prostrations after he had said the Salam." (ES)
Reference (ES): Jami` at-Tirmidhi 392 (ES)
In-book reference (ES): Book 2, Hadith 245 (ES)
English translation (ES): Vol. 1, Book 2, Hadith 392 (ES)