Lubaba bint Harith reported,
Husayn bin Ali 
was in the lap of the Messenger of Allah ﷺ when he urinated on him. I said, "Put on a garment and give me your lower wrap so I may wash it."He replied, "Only the urine of a female is washed. The urine of a male is sprinkled with water."
Abu Dawud 375
Hasanحدثنا مسدد بن مسرهد والربيع بن نافع أبو توبة المعنى قالا حدثنا أبو الأحوص عن سماك عن قابوس
عن لبابة بنت الحارث قالت
كان الحسين بن علي رضي الله عنه في حجر رسول الله ﷺ فبال عليه فقلت البس ثوبا وأعطني إزارك حتى أغسله قال إنما يغسل من بول الأنثى وينضح من بول الذكر
[Hasan]. Ibn Majah narrated it in the Book of Purification, chapter on the urine of the infant who has not yet eaten [solid food], no. 522, from the hadith of Abu Ahwas with this wording. Ibn Khuzayma graded it sahih, no. 282, as did Hakim, 1/166, and Dhahabi agreed with him. The hadith has other routes of transmission in Bayhaqi, 2/415, and elsewhere.