Musnad Ahmad 595:14

Khalaf ibn al-Walid narrated to us, 'Abbad ibn 'Abbad—meaning al-Muhallabi—narrated to us, al-Mujalid ibn Sa'id narrated to us, from Qays ibn Abi Hazim, from al-Mustawrid ibn Shaddad, who said: I heard the Messenger of Allah (peace and blessings of Allah be upon him) say: "By Allah, the worldly life in comparison to the Hereafter is nothing but like a man who puts his finger into the sea, then it returns to him; so what did it take from it?" He said: And al-Mustawrid said: I bear witness that I was with the riders who were with the Messenger of Allah (peace and blessings of Allah be upon him) when he passed by the dwelling of a people who had departed from it, and there was a dead kid (young goat) cast aside. He said: "Do you see this? Was it insignificant to its owners when they cast it away?" They said: It was because of its insignificance to them that they cast it away. He said: "By Allah, the worldly life is more insignificant to Allah than this is to its owners."