From Sahih Bukhari (Hadith 812):
Narrated Ibn `Abbas:The Prophet (ﷺ) said, "I have been ordered to prostrate on seven bones i.e. on the forehead along with the tip of the nose and the Prophet (ﷺ) pointed towards his nose, both hands, both knees and the toes of both feet and not to gather the clothes or the hair
Reference: Bukhari 812