Sunan Abi Dawud
Hadith #5218
Abu Hurairah said; Al-Aqra’ b. Habib saw that the Messenger of Allah(ﷺ) was kissing Husain. He said:I have ten children and I have never kissed any of them. The Messenger of Allah(ﷺ) said: He who does not show tenderness will not be shown tenderness