Musnad Ahmad 772:2

Abdullah said: Mansur ibn Abi Muzahim narrated to us, he said: 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 Allah bless him and grant him peace, said upon the pulpit: "Whoever does not thank for the little will not thank for the much, and whoever does not thank the people will not thank Allah, the Mighty and Majestic. Speaking of the blessing of Allah is gratitude, and abandoning it is disbelief. And the community is a mercy, and division is a punishment."