From Umm 'Abdillah Al-Waadi'iyyah's "Naseehati Lin-Nisaa' " (My Advice to the Women). I typed this excerpt from the english translation published by Tarbiyyah Bookstore. To save time in typing, I omitted the chains of narration for the ahadeeth (but still included all references), as some of them were rather long. Other than that, I didn't deviate from the translated text, translated by the brother Abul-Layth. [ Taken from here]
Chapter: Whoever Does Not Show Mercy Will Not Be Shown Mercy (pages 117-122):
Aboo Hurayrah narrated that the Messenger of Allah, salallahu 'alaihi wa salam, kissed Al-Hasan while Al-Aqra ibn Haabis at-Tameemee was sitting near him. A-Aqra said, "Indeed I have ten children and I have never kissed any of them." The Messenger of Allah looked at him and said, "Whoever does not show mercy will not be shown mercy." [Saheeh al-Bukhaari, 426/10]
From Shaddaad ibn Aws who said that the Messenger of Alah, salallahu 'alaihi wa salam, said, "Verily Allah has perscribed al-ihsaan (excellence) for everything. So when you kill, you should kill in the best manner. And when you slaughter, you should slaughter in the best manner. Let each of you sharpen his knife to provide ease for his animal." [Saheeh Muslim]
"Al-ihsaan" or "excellence" in the arabic language is procifency in performing an action, while perfecting it with sincerity. In Islaamic law, Al-Ihsaan is what the Prophet, salallahu 'alaihi wa salam, has explained in his statement: "That you worship Allah as though you see Him, but since you are un able to see Him, then He most certainly sees you."
Ibn Rajab said concerning the prophetic narration of Shaddaad, "This prophetic narration indicates the obligation of excellence in all of the actions." [Jami'Al-Uloom 151]
From the types of mercy which can be shown to a child is kissing him: 'Aa'ishah said that a Bedouin man came to the Prophet, salallahu 'alaihi wa salam, and said, "You (people) kiss the children and we do not kiss them." So the Prophet said, "Is there anything that I can do once Allah has removed mercy from your heart?" [Saheeh Al-Bukhari 426/10]
'Umayr ibn Ishaaq said, "I was with Al-Hasan ibn 'Alee when we met with Aboo Hurayrah who said, "Show me where I might kiss you in the place where I saw the messenger of Allah kiss." He replied, "Al-Qameesah" (shirt or upper garment), He said, "So he kissed the front of his stomach." [Ahmed with a hasan chain]
From the types of mercy that can be shown to a child is carrying him while in prayer. Abu Qataadah said that the Prophet, salallahu 'alaihi wa sallam, came out to us with Umaamah bint Abeel-'Aas on his shoulders. Then he prayed. When he bowed, he placed her on the ground and when he rose from bowing, he lifted her back off the ground." [Saheeh Al-Bukhaari]
On the authority of Abu Shaddaad, from his father, who said that the Prophet, salallahu 'alaihi wa sallam, came out to us for one of the 'ishaa prayers carrying Hasan and Husayn. The Messenger of Allah stepped forward and set them both down. Then he prayed and prostrated between their backs a single prostration that was lengthy. My (Abu Shaddaad's) father said, 'Then I raised my head and the child was on the back of the Messenger of Allah while he was prostrating. I then returned to my prostration.' So once the Messenger of Allah had completed his prayer, the people said, 'O Messenger of Allah, certainly you have prostrated between two backs in your prayer. Certainly the length of this prostration led us to believe that something had happened or that revelation had decended upon you.' He, salallahu 'alaihi wa sallam, said, 'None of that occured, rather this child moved around me and I didn't wish to disturb him until he had finished.' [hadeeth collected in An-Nasaa'ee, authenticated by Shaykh Muqbil]
From the types of mercy that can be shown to smaller children is playing with them: Umm Khaalid bint Khaalid ibn Sa'eed said, "I came to the Messenger of Allah, salallahu 'alaihi wa sallam, along with my father and I was wearing a yellow shirt. The messenger of Allah said, 'Sanah, sanah!' (this means 'good' in the ethiopian langauge) Umm Khaalid further said, 'Then I started playing with the seal of Prophethood. My father admonished me, but the Messenger of Allah said (to my father) 'Leave her.' The Messenger of Allah then addressed me saying, 'Ablee wa akhliqee, thumma ablee wa akhliqee, thumma ablee wa akhliqee.' (Trans. note: This phrase 'ablee wa akhliqee' is used by the arabs to supplicate for an extended life. Its meaning could be conveyed in the following expression: 'May you live so long that your garments become worn and ragged.') So she (Umm Khaalid) remained this way until (this supplication for her became actualized and subsequently) she would be mentioned by the people," meaning that she would remain until her garments became old and ragged. [Saheeh Al-Bukhaari 425/10]
Mahmood ibn Ar-Rabee' said, "I remember when I was a boy of Five years old, the Prophet, salallahu 'alaihi wa sallam, took water from a bucket with his mouth (majjatan majjahaa) and threw it in my face."
Al-Haafidh said, " 'Majj' is the expelling of water from the mouth. It is said that nothing is refered to as 'majj' except if it is from a distance. The action of the Prophet, salallahu 'alaihi wa sallam, with Mahmood was either from his play with him or it was a means of blessing him with it just as he used to do with the children of his companions."
Anas ibn Maalik said, "Certainly the Prophet, salallahu 'alaihi wa sallam, used to spend time with us to the extent that he even said to my young brother, 'Oh father of 'Umayr, what did the little birdie do?' " [Saheeh Al-Bukhaari 526/10]
In addition, from the types of mercy that can be shown to a child is placing the child in one's lap. 'Usaamah ibn Zayd said that the Messenger of Allah, salallahu 'alaihi wa sallam, used to take me and place me on his thigh and he would place al-Hasan ibn 'Alee on his other thigh, then he would come close to us and say, "Oh Allah! Please be merciful to them, for indeed, I am merciful to them." [Saheeh Al-Bukhaari 434/10]
Therefore, this is how one might be affectionate with the smaller children concerning everything they might need or how they might be amused. This is an appropiate means of showing them mercy and affection, as long as this does not lead towards bringing about improper behavior.
Certainly the Prophet, salallahu 'alaihi wa sallam, has praised the women of Quraysh because they possessed praiseworthy characteristics and from them is their affection for children.
Narrated upon Abu Hurayrah that the Messenger of Allah, salallahu 'alaihi wa sallam, said, "The best wome to ever ride the camel were the women of Quraysh." [Saheeh Al-Bukhari 511/9]
He also said, "The most righteous from the women of Quraysh are those who are most affectionate ("ahnaah") to the child during its youth and who are most protective concerning their husband's property." Al-Haafidh said that "ahnaah" is from affection, which is compassion and tenderness.
The mercy that is shown to the young children and other than them is from the reasons that cause a person to achieve the mercy of Allah.
It has also reached us from the Prophet, slallahu 'alaihi wa sallam, that he said, "He is not from us who does not show mercy to the young and does not honor the old."