It was narrated that Al-Hakam bin Sufyan said:
"I saw the Messenger of Allah (ﷺ) performing Wudu' and sprinkling his private area (with water)." (RU)
English reference (RU): Vol. 1, Book 1, Hadith 135 (RU)
Arabic reference (RU): Book 1, Hadith 136 (RU)