Muwatta Imam Malik (Riwayat Ibn al-Qasim)

And with the same chain of narration, it is narrated from Umm Qais bint Mihsan (may Allah be pleased with her) that she came to the Messenger of Allah (peace and blessings be upon him) with her small child who had not yet started eating food. The Messenger of Allah (peace and blessings be upon him) seated the child in his lap, and then the child urinated on his clothes. So the Messenger of Allah (peace and blessings be upon him) called for water, sprinkled water on the clothes, and did not wash them.