Sahih Muslim Book 20, Hadith Number 4517.

Chapter : Obedience to the ruler is forbidden in matters sinful, but is otherwise obligatory.

It has been narrated on the authority of Ibn Juraij that the Qur’anic injunction: “O you who believe, obey Allah, His Apostle and those in authority from amongst You” (iv. 59)-was revealed in respect of ‘Abdullah b. Hudhafa b. Qais b. Adi al-Sahmi who was despatched by the Holy Prophet (may peace be upon him) as leader of a military campaign. The narrator said: He was informed of this fact by Ya’la b. Muslim who was informed by Sa’id b. Jubair who in turn was informed by Ibn Abbas.