صحيح ابن خزيمه
Sahih Ibn Khuzaymah
جماع أبواب السهو فى الصلاةChapters on Forgetfulness in Prayer
(433) بَابُ إِيجَابِ سَجْدَتَيِ السَّهْوِ عَلَى الْمُسَلِّمِ قَبْلَ الْفَرَاغِ مِنَ الصَّلَاةِ سَاهِيًا،The chapter on the obligation of two prostrations of forgetfulness before finishing the prayer if one forgets
Hadith Q1035
وَالدَّلِيلِ أَنَّ هَاتَيْنِ السَّجْدَتَيْنِ إِنَّمَا يَسْجُدُهُمَا الْمُصَلِّي بَعْدَ السَّلَامِ لَا قَبْلُ
And the explanation of the evidence that the worshipper will perform these two prostrations after saying the salutation, not before.
