Buraydah (radiallahu anhu) says, "Najaashi sent two simple black coloured socks as a gift to Sayyidina Rasulullah sallallahu alaihe wasallam. He wore these and made mash over them after performing wudu". (TR)
English reference (TR): Book 9, Hadith 69 (TR)
Arabic reference (TR): Book 10, Hadith 73 (TR)