Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) used to show his tongue to Sayyiduna Imam Hussain (may Allah be pleased with him) by sticking it out. When the child saw the redness of your tongue, he would become happy. ‘Uyainah bin Hisn submitted to you, “I did not expect that you would behave with him in this manner. By Allah! I also have a son but I have never kissed him.” The Prophet (peace and blessings be upon him) said: Whoever does not show mercy will not be shown mercy.
Hadith Referenceصحیح ابن حبان / كتاب الحظر والإباحة / 5596
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «الصحيحة» (70). قال الناشر: هذا الحديث -والذي قبله- ساقطان من «الأصل»، واستدركناهما من «طبعة المؤسسة».فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده حسن