Narrated Ibn 'Abbas (RA):

Allah's Messenger (ﷺ) said: "I have been commanded to prostrate on seven bones; on the forehead - and he pointed at his nose, the hands (the palms), the knees and the tips (toes) of the feet." [Agreed upon].

وَعَنْ اِبْنِ عَبَّاسٍ ‏-رَضِيَ اَللَّهُ عَنْهُمَا‏- قَالَ: قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ أُمِرْتُ أَنْ أَسْجُدَ عَلَى سَبْعَةِ أَعْظُمٍ : عَلَى اَلْجَبْهَةِ ‏- وَأَشَارَ بِيَدِهِ إِلَى أَنْفِهِ ‏- وَالْيَدَيْنِ , وَالرُّكْبَتَيْنِ , وَأَطْرَافِ اَلْقَدَمَيْنِ } مُتَّفَقٌ عَلَيْهِ .‏ [1]‏