Nafi' (may Allah have mercy on him) says that whenever Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) bought a slave-girl, he would remove the cloth from her shin and place his hand between her breasts and on her buttocks, and this was over the garment.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10789