Aamir bin Sa’d narrates this statement from Sayyiduna Abbas bin Abdul Muttalib (may Allah be pleased with him), who heard the Prophet Muhammad (peace and blessings be upon him) say: “When a servant prostrates, seven parts of his body prostrate along with him: his face, his two knees, his two palms, and his two feet.”
Hadith Referenceصحیح ابن حبان / كتاب الصلاة / 1921
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «صحيح أبي داود» (830): م.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرطهما، ابن الهاد: هو يزيد بن عبد الله بن أسامة بن الهاد المدني.