Sayyidah Umm Qays bint Mihsan (may Allah be pleased with her) said: I brought a son of mine, who did not yet eat food, to the Messenger of Allah (peace and blessings be upon him), and he (peace and blessings be upon him) seated him in his lap, and he urinated on the garment of the Messenger of Allah (peace and blessings be upon him). So he (peace and blessings be upon him) called for water, sprinkled it over his garment, and did not wash it.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21905