Aqra bin Habis saw the Prophet ﷺ kissing Hasan. Ibn Abu Umar said, Husayn or Hasan. He said, "I have ten children, and I have never kissed any of them."The Messenger of Allah ﷺ replied, "Whoever shows no mercy will be shown no mercy."
حدثنا ابن أبي عمر وسعيد بن عبد الرحمن قالا حدثنا سفيان عن الزهري عن أبي سلمة
أبصر الأقرع بن حابس النبي ﷺ وهو يقبل الحسن قال ابن أبي عمر الحسين أو الحسن فقال إن لي من الولد عشرة ما قبلت أحدا منهم فقال رسول الله ﷺ إنه من لا يرحم لا يرحم
Agreed upon [by Bukhari and Muslim]. Muslim also reported it in "the Book of Virtues," chapter on his mercy toward children and family, and his humility, and the merit of that, hadith no. 2318, from Muhammad bin Yahya bin Abu Umar. Bukhari reported it as hadith no. 5997, from the hadith of Zuhri, with the same wording.There is also a report on this subject from Anas [coming up: 3772] and Ayesha [Bukhari, no. 5998, and Muslim, no. 2317].