Narrated Abu Uthman: Usama bin Zaid said that while he, Sa’d and Ubai bin Ka’b were with the Prophet (peace be upon him) a daughter of the Prophet (peace be upon him) sent a message to him, saying. ‘My daughter is dying; please come to us.” The Prophet (peace be upon him) sent her his greetings and added “It is for Allah what He takes, and what He gives; and everything before His sight has a limited period. So she should hope for Allah’s reward and remain patient.” She again sent a message, beseeching him by Allah, to come. So the Prophet (peace be upon him) got up. and so did we (and went there). The child was placed on his lap while his breath was irregular. Tears flowed from the eyes of the Prophet. Sa’d said to him, “What is this, O Allah’s Apostle?” He said, “This is Mercy which Allah has embedded in the hearts of whomever He wished of His slaves. And Allah does not bestow His Mercy, except on the merciful among His slaves. (See Hadith No. 373 Vol. 2)

Sahih Al-Bukhari – Book 70 Hadith 559