The Prophet ﷺ said, "I have been commanded to prostrate on seven bones."
حدثنا بشر بن معاذ الضرير حدثنا أبو عوانة وحماد بن زيد عن عمرو بن دينار عن طاوس
عن النبي ﷺ قال أمرت أن أسجد على سبعة أعظم
Bukhari narrated it in the Book of Adhan, chapter "One should not tuck up hair," hadith numbers 815 and 816, and Muslim narrated it in the Book of Prayer, chapter on the limbs of sujud, hadith number 490, from the hadith of Hammad bin Zayd and others, with this wording.