Abu Hurairah reported,
The Messenger of Allah ﷺ kissed Husayn bin Ali 
while Aqra bin Habis al-Tamimi was sitting nearby.Aqra remarked, "Messenger of Allah, I have ten children, and I have never kissed any one of them."The Messenger of Allah ﷺ looked at him and said, "Whoever shows no mercy will receive no mercy."
Ahmad 7649
Sahihحدثنا عبد الرزاق أخبرنا معمر عن الزهري حدثني أبو سلمة
عن أبي هريرة
أن رسول الله ﷺ قبل الحسين بن علي رضي الله عنهما والأقرع بن حابس التميمي جالس فقال الأقرع يا رسول الله إن لي عشرة من الولد ما قبلت إنسانا منهم قط قال فنظر إليه رسول الله ﷺ فقال إن من لا يرحم لا يرحم
Its isnad is sahih, and it is a duplicate of 7121 and 7287. We have already noted this at the first of the two. In H, it reads Husayn instead of Hasan, which is a printing error, and we have corrected it based on M and the sources of the hadith.