Musannaf Ibn Abi Shayba 33:156

Sufyan ibn 'Uyaynah narrated to us, from Muhammad ibn 'Ajlan, from 'Iyad ibn 'Abd Allah, from Abu Sa'id al-Khudri, who said: The Messenger of Allah (may Allah bless him and grant him peace) said while he was on the pulpit: "Indeed, the thing I fear most for you is what Allah brings forth for you from the vegetation of the earth, or the flower of the world." A man stood up and said: "O Messenger of Allah, does good bring about evil?" He remained silent until we thought that revelation was descending upon him, and he was overcome by heavy breathing and sweat. Then he said: "Where is the questioner? He intended nothing but good." The man said: "Here I am, and I intended nothing but good." He said: "Indeed, good does not bring about anything but good. However, the world is green and sweet. Whatever the spring brings forth kills or nearly kills, except for the animal that eats the green vegetation; it eats until, when its flanks are full, it faces the sun, then it defecates, then it urinates, then it ruminates. Whoever takes wealth by its right, it is blessed for him; and whoever takes wealth without its right, he is like one who eats but is never satisfied."