(1) بَابُ مَا جَاءَ فِي إِجَازَةِ خَبَرِ الْوَاحِدِ الصَّدُوقِ فِي الأَذَانِ وَالصَّلاَةِ وَالصَّوْمِ وَالْفَرَائِضِ وَالأَحْكَامِ
Narrated `Abdullah:
The Prophet (ﷺ) led us in Zuhr prayer and prayer five rak`at. Somebody asked him whether the prayer had been increased." He (the Prophet (ﷺ) ) said, "And what is that?" They (the people) replied, "You have prayed five rak`at." Then the Prophet (ﷺ) offered two prostrations (of Sahu) after he had finished his prayer with the Taslim.
Reference: Sahih al-Bukhari 7249
In-book reference: Book 95, Hadith 4
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 9, Book 91, Hadith 355