It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that "The limbs on which the Prophet (peace and blessings be upon him) was commanded to prostrate are seven." Ibn Maysarah (may Allah have mercy on him) says: I asked: O Abu Abd al-Rahman! Is the nose also included among them? He said: It is all the more so.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2650