Musnad Ahmad 1268:2

Abu Bakr al-Hanafi narrated to us, he said: Usamah ibn Zayd narrated to us, from ‘Amr ibn Shu’ayb, from Umm Kurz al-Khuza’iyyah, who said: "A boy was brought to the Prophet, peace and blessings of Allah be upon him, and he urinated on him, so he ordered it to be sprinkled with water. Then a girl was brought and she urinated on him, so he ordered it to be washed."