Majma al-Zawaid — Hadith 290

Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates that the Prophet (peace and blessings be upon him) said: "The religion is sincere goodwill (nasihah)." The people asked: "To whom?" The Prophet (peace and blessings be upon him) said: "To Allah Almighty, to His Messenger, and to the rulers of the believers." Imam Ahmad and al-Bazzar recorded it, and al-Tabarani in al-Mu'jam al-Kabir, and he recorded these words: "To the rulers of the Muslims and their common folk."
In its chain Imam Ahmad recorded these words: It is narrated from Amr bin Dinar, who said: The one who heard Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrating it told me. Whereas al-Tabarani recorded these words: This narration is from Amr bin Dinar, from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both). The narration of Imam Ahmad implies that there is a break (inqita') between Amr bin Dinar and Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both). Along with that, its chain contains a narrator, Abd al-Rahman bin Thabit bin Thawban, whom Imam Ahmad declared da'if (weak); he said: His narrations are munkar (denounced).
Abu Ya'la recorded it, and its narrators are the narrators of the Sahih. The words recorded by Abu Ya'la are: "The people asked: 'O Messenger of Allah! To whom?' He (peace and blessings be upon him) said: 'To the Book of Allah, to His Prophet, and to the rulers of the Muslims.'"