سنن النسائي

It was narrated that Abu 'Uthman said: "Usamah bin Zaid told me: 'The daughter of the Prophet (ﷺ) sent word to him telling him: A son of mine is dying, come to us. He sent word to her, conveying his greeting of salam and saying: "To Allah belongs that which He takes and that which He gives, and everything has an appointed time with Allah. Let her be patient and seek reward." She sent word to him adjuring him to go to her. So he got up and went, accompanied by Sa'd bin 'Ubadah, Muadh bin Jabal, Ubayy bin Kab Zaid bin Thabit and some other men. The boy was lifted up to the Messenger of Allah, with the death rattle sounding in him, and his eyes filled with tears. Sa'd said: "O Messenger of Allah, what is this?" he said: "This is compassion which Allah has created in the hearts of His slaves. Allah has mercy on His compassionate slaves."