Sahih Muslim 571
Sahih Muslim · Book 5: The Book of Mosques and Places of Prayer · As-Sahw (forgetfulness) in prayer and prostrating to compensate for it
This hadith has been narrated by Zaid b. Aslam with the same chain of transmitters and he said:
حَدَّثَنِي أَحْمَدُ بْنُ عَبْدِ الرَّحْمَنِ بْنِ وَهْبٍ ، حَدَّثَنِي عَمِّي عَبْدُ اللَّهِ ، حَدَّثَنِي دَاوُدُ بْنُ قَيْسٍ ، عَنْ زَيْدِ بْنِ أَسْلَمَ ، بِهَذَا الإِسْنَادِ وَفِي مَعْنَاهُ قَالَ " يَسْجُدُ سَجْدَتَيْنِ قَبْلَ السَّلاَمِ " . كَمَا قَالَ سُلَيْمَانُ بْنُ بِلاَلٍ .
He should perform two prostrations before the salutation, as it was mentioned by Sulaiman b. Bilal.