Mercy

From the Al-Adab al-Mufrad al-Bukhari (Muslim Morals and Manner of al-Bukhari) chapter on Mercy:

174. The Most Merciful of those in the earth

372. 'Umar was heard to say, "Anyone who does not show mercy will not be shown mercy. Anyone who does not forgive will not be forgiven. Anyone who does not turn in repentance will not be turned to nor will he be protected or guarded."

373. Mu'awiya ibn Qurra reported that his father said, "A man said, 'Messenger of Allah, I was going to slaughter a sheep and then I felt sorry for it (or 'sorry for the sheep I was going to slaughter').' He said twice, 'Since you showed mercy to the
sheep, Allah will show mercy to you.'"

374. Abu Hurayra said, "I heard the Prophet, may Allah bless him and grant him peace, the truthful confirmed one, Abu'l-Qasim, may Allah bless him and grant him peace, say, 'Mercy is only removed from the one who is destined for wretchedness."

375. Jarir reported that the Prophet, may Allah bless him and grant him peace, said, "Allah will not show mercy to a person who does not show mercy to other people."