Sayyiduna Ibn Abbas (may Allah be pleased with them both) said that the Noble Prophet (peace and blessings be upon him) was commanded to prostrate on seven parts of the body, in such a way that neither did he gather his hair nor his clothes. (Those seven parts are:) the forehead (along with the nose), both hands, both knees, and both feet.
Hadith Referenceاللؤلؤ والمرجان / كتاب الصلاة / 276
Hadith Gradingمحدثین:«صحیح»
Hadith Takhrij«صحیح، أخرجه البخاري في: 10 كتاب الأذان: 133 باب السجود على سبعة أعظم»