(133) باب السُّجُودِ عَلَى سَبْعَةِ أَعْظُمٍ
Narrated Ibn `Abbas:
The Prophet (ﷺ) was ordered (by Allah) to prostrate on seven parts and not to tuck up the clothes or hair (while praying). Those parts are: the forehead (along with the tip of nose), both hands, both knees, and (toes of) both feet. (RU)
Reference (RU): Sahih al-Bukhari 809 (RU)
In-book reference (RU): Book 10, Hadith 204 (RU)
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 12, Hadith 773 (RU)