Arabic text
عن جرير بن عبد الله رضي الله عنه قال: قال رسول الله صلى الله عليه وسلم: «مَنْ لَا يَرْحَمِ النَّاسَ لَا يَرْحَمْهُ اللهُ عَزَّ وَجَلَّ».
Translation
Jarīr ibn ‘Abdullāh (may Allah be pleased with him) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) said: "Whoever does not show mercy to people, Allah Almighty does not show mercy to him."
Explanation
The Prophet (may Allah's peace and blessings be upon him) informs that Allah Almighty does not show him who does not show mercy to people mercy. Indeed, showing compassion to people is one of the greatest means of receiving Allah's mercy.
Source: HadeethEnc.com