Allah's Messenger (peace be upon him) kissed Al-Hasan ibn `Ali while Al-Aqra` ibn Habis At-Tamimi was sitting with him. Al-Aqra` said, “I have ten children and have never kissed one of them.” The Prophet cast a look at him and said, “Whoever is not merciful to others will not be treated mercifully.”
(Al-Bukhari)