Musnad Ahmad 26:216

Abu al-Nadr narrated to us, al-Mas'udi narrated to us, from al-Hasan ibn Sa'd, from 'Abd al-Rahman ibn 'Abd Allah, from 'Abd Allah, that he said: The Prophet, peace and blessings of Allah be upon him, stopped at a place, then he went off to relieve himself. He came back, and a man had set fire to an anthill, either on the ground or in a tree. The Messenger of Allah, peace and blessings of Allah be upon him, said: "Which of you did this?" A man from the people said: "I did, O Messenger of Allah." He said: "Extinguish it, extinguish it."