Al-Lu'lu Wal-Marjan 531 — The Book of Funerals (Al-Janâ'iz)

Usamah bin Zaid Narrated from:

The daughter of the Prophet صلى الله عليه وسلم sent (a messenger) to the Prophet صلى الله عليه وسلم requesting him to come as her child was dying (or was gasping), but the Prophet صلى الله عليه وسلم returned the messenger and told him to convey his greeting to her and say: "Whatever Allâh takes is for Him and whatever He gives, is for Him, and everything with Him has a limited fixed term (in this world), and so, she should be patient and hope for Allâh's Reward."She again sent for him, swearing that he should come. The Prophet صلى الله عليه وسلم got up, and so did Sa'd bin 'Ubâda, Mu'âdh bin Jabal, Ubai bin Ka'b, Zaid bin Thâbit and some other men. The child was brought to Allâh's Messenger صلى الله عليه وسلم while his breath was disturbed in his chest (the subnarrator thinks that Usâma added:) as if it was a leather water-skin. On that the eyes of the Prophet صلى الله عليه وسلم started shedding tears.Sa'd said, "O Allâh's Messenger! What is this?" He replied, "It is the mercy which Allâh has lodged in the hearts of his slaves, and Allâh تعالى is Merciful only to those of His slaves who are merciful (to others). ( Sahih Al-Bukhâri, Hadîth No. 373, Vol. 2 )