Sunan Ibn Majah
1206
Sahih+3

It was narrated from Ibn Buhainah:“The Prophet (ﷺ) offered prayer, I think it was the ‘Asr, and in the second Rak’ah he stood up before he sat. Before he said the Salam, he prostrated twice.”

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi