It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that when the Noble Prophet (peace and blessings be upon him) tied his lower garment, the calf muscle of his shin would be visible from beneath the garment.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 8706
Hadith Gradingحکم دارالسلام:إسناده ضعيف لرواية زهير عن صالح بعد الاختلاط