Sunan Ibn Majah
885
Sahih+2

It was narrated from ‘Abbas bin ‘Abdul-Muttalib that he heard the Prophet (ﷺ) say:“When a person prostrates, seven parts of his body prostrate with him: His face, his two hands, his two knees, and his two feet.”

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi