The Cleansing of Impurities - Section 1 Mishkat al-Masabih 497
Translation
Umm Qais daughter of Mihsan told how she brought a young son of hers who was not yet weaned to God’s messenger. He set him on his lap, and the child passed water on his garment; so he called for water and sprinkled it, but did not wash it. (Bukhari and Muslim.)