Riyad as-Salihin
The Book of Greetings
كتاب السلام
Chapter 143: The Excellence of Shaking Hands When Greeting Someone
Abu Hurairah (May Allah be pleased with him) reported
The Prophet (ﷺ) kissed his grandson Hasan bin 'Ali in the presence of Aqra' bin Habis. Thereupon Aqra' remarked: "I have ten children and I have never kissed any one of them." The Messenger of Allah (ﷺ) cast a glance upon him and said, "He who does not show mercy to others, will not be shown mercy."[Al-Bukhari and Muslim].