From The Saying of The Messenger of Allah (pbuh) (28)

عن أبي هريرة رضي الله عنه قال : " قبل رسول الله صلى الله عليه وسلم الحسن بن علي وعنده الأقرع بن حابس التميمي جالسا ، فقال الأقرع : إن لي عشرة من الولد ما قبلت منهم أحدا ، فنظر إليه رسول الله صلى الله عليه وسلم ثم قال : ( من لا يرحم لا يرحم ) . الراوي: أبو هريرة المحدث: البخاري - المصدر: صحيح البخاري - الصفحة أو الرقم: 5997 خلاصة حكم المحدث: [صحيح
] Abu Hurairah (May Allah be pleased with him) reported: "The Prophet (PBUH) kissed his grandson Al-Hasan bin `Ali (May Allah be pleased with them) in the presence of Al-Aqra` bin Habis. Thereupon he remarked: "I have ten children and I have never kissed any one of them.'' Messenger of Allah (PBUH) looked at him and said, "He who does not show mercy to others will not be shown mercy" (Al-Bukhari and Muslim) . Commentary: 1) Islam is the religion of Mercy .Mercy is for not only humans but also for animals and Allah (pbth) is the Merciful and beneficent and the word "Mercy " was mentioned in the Quran 79 times also Allah (pbth) inscribed for Himself (the rule of) Mercy as he said in the Quran :
"قُلْ لِمَنْ مَا فِي السَّمَاوَاتِ وَالْأَرْضِ ۖقُلْ لِلَّهِ ۚكَتَبَ عَلَىٰ نَفْسِهِ الرَّحْمَةَ ۚلَيَجْمَعَنَّكُمْ إِلَىٰ يَوْمِ الْقِيَامَةِ لَا رَيْبَ فِيهِ ۚالَّذِينَ خَسِرُوا أَنْفُسَهُمْ فَهُمْ لَا يُؤْمِنُونَ" (6/12)
Say: "To whom belongeth all that is in the heavens and on earth?" Say: "To Allah. He hath inscribed for Himself (the rule of) Mercy that He will gather you together for the Day of Judgment, there is no doubt whatever. It is they who have lost their own souls that will not believe" (6/12 )

2) And the messenger of Allah (pbuh) is the messenger of mercy for all creatures as he is the final messenger of Allah in that universe and he is the seal of all messengers and prophets Allah praised him in the Quran saying
:
"وَمَا أَرْسَلْنَاكَ إِلَّا رَحْمَةً لِّلْعَالَمِينَ" ( 21/107)
We sent thee not, but as a mercy for all creatures"
(21/107) َ"فِمَا رَحْمَةٍ مِنَ اللَّهِ لِنْتَ لَهُمْ ۖوَلَوْ كُنْتَ فَظًّا غَلِيظَ الْقَلْبِ لَانْفَضُّوا مِنْ حَوْلِكَ" (3/159)
"Thus it is due to mercy from Allah that you deal with them gently, and had you been rough, hard hearted, they would certainly have dispersed from around you;
" (3/ 159) "مَا كَانَ مُحَمَّدٌ أَبَا أَحَدٍ مِنْ رِجَالِكُمْ وَلَٰكِنْ رَسُولَ اللَّهِ وَخَاتَمَ النَّبِيِّينَ ۗوَكَانَ اللَّهُ بِكُلِّ شَيْءٍ عَلِيمًا" (33/40)
"Muhammad is not the father of any of your men, but (he is) the Messenger of Allah, and the Seal of the Prophets: and Allah has full knowledge of all things"
3) Also Allah (pbth) divided the mercy into 100 parts .He (pbth ) kept 99 parts with him to be merciful for the people of the day of Resurrection and sent down one part to the land. From that part we all are merciful towards each others and the the mare lifts up its hoofs away from its baby animal, lest it should trample on it . --------------------------------------------------------------------------------------------------------
قال رسول الله صلي الله عليه وسلم : "جعل الله الرحمة في مائة

جزء ، فأمسك عنده تسعة وتسعين جزءا ، وأنزل في الأرض جزءا واحدا ، فمن ذلك الجزء يتراحم الخلق ، حتى ترفع الفرس حافرها عن ولدها ، خشية أن تصيبه " الراوي: أبو هريرة المحدث: البخاري - المصدر: صحيح البخاري - الصفحة أو الرقم: 6000 خلاصة حكم المحدث: [صحيح
] The messenger of Allah (pbuh ) said : "Allah divided Mercy into one-hundred parts and He kept its ninety-nine parts with Him and sent down its one part on the earth, and because of that, its one single part, His creations are Merciful to each other, so that even the mare lifts up its hoofs away from its baby animal, lest it should trample on it" ---------------------------------------------------------------------------------------------------------
عن عائشة زوج النبي (رضي الله عنها ) قالت : " قدم ناس من الأعراب على رسول الله صلى الله عليه وسلم . فقالوا أتقبلون صبيانكم ؟ فقالوا : نعم . فقالوا : لكنا ، والله ! ما نقبل . فقال رسول الله صلى الله عليه وسلم " وماأملك إن كان الله نزع منكم الرحمة " وقال ابن نمير " من قلبك الرحمة " . الراوي: عائشة المحدث: مسلم - المصدر: صحيح مسلم - الصفحة أو الرقم: 2317 خلاصة حكم المحدث: صحيح
Aishah (May Allah be pleased with her) reported: Some bedouins came to Messenger of Allah (PBUH) and asked: "Do you kiss your children?'' He said, "Yes". They then said: "By Allah, we do not kiss them.'' The Prophet (PBUH) replied, "I cannot help you if Allah has snatched kindness from your hearts" (Al-Bukhari and Muslim) Commentary: Then all the atmosphere in Islam is the atmosphere of love , compassion , affection and mercy and kissing children is a sign of all these feelings that Allah endows mankind. .