It was narrated that 'Ubaid bin Juraih said: "I said to Ibn 'Umar: “I see you are wearing Sibtiyyah sandals, [1] and you performed Wudu' in them.' He said: “I saw the Messenger of Allah (ﷺ) wearing then and performing Wudu' in them.'" [1] Made of hairless, tanned leather””
SahihSahihSahih - Agreed UponBook 1 · Hadith 117