Musnad Ahmad 595:6

'Affan narrated to us, Hammad bin Zayd narrated to us, Mujalid bin Sa'id narrated to us, from Qays bin Abi Hazim, from al-Mustawrid bin Shaddad, who said: I was in a company with the Messenger of Allah (peace and blessings of Allah be upon him) when he passed by a dead, discarded kid (young goat). The Messenger of Allah (peace and blessings of Allah be upon him) said: "Do you see this as being insignificant to its owners?" They said: "O Messenger of Allah, it is because of its insignificance that they threw it away." He said: "Then by the One in Whose hand is the soul of Muhammad, the world is more insignificant to Allah than this is to its owners."