Musnad Abu Ya'la al-Mawsili 152:88

Abu Khaythama narrated to us, Waki' and Yahya bin Sa'id narrated to us, from al-A'mash, from Zayd bin Wahb, from 'Abdullah, who said: The Messenger of Allah (ﷺ) said: "There will be, after me, favoritism and matters that you will disapprove of." They said: "O Messenger of Allah, what do you command those of us who reach that?" He said: "You shall fulfill the right that is upon you, and you shall ask Allah for that which is yours."