Musnad Ahmad 652:103

Abdullah said: Mansur ibn Abi Muzahim narrated to us, Abu Waki’ al-Jarrah ibn Mulayh narrated to us, from Abu Abd al-Rahman, from al-Sha’bi, from al-Nu’man ibn Bashir, who said: The Prophet, may God bless him and grant him peace, said upon the pulpit: "Whoever does not thank for the little, does not thank for the much. And whoever does not thank the people, does not thank God. Speaking of the blessing of God is gratitude, and abandoning it is disbelief. The community is a mercy, and division is a punishment."