Council - 42:15
"Call to it and follow it as you have been commanded. Do not follow their desires and say: "I believe in the Book which Allah has sent down to me, and I am commanded to do justice among you. Allah is our Lord and your Lord. What we have done is for us and what you have done is for you. There is no dispute between us and you. Allah will bring us together. To Him is the final return."
When you judge, judge by the Book (Qur'an).
The Cow/2:213
Mankind were a single community. Allah sent messengers as bearers of glad tidings and warners and sent down with them the Book containing the truth so that they might judge between the people in matters wherein they differed. But those who were given the Book disputed about it out of envy among themselves after clear proofs had come to them. But Allah, by His permission, brought the believers to the truth about which they differed. Allah guides whom He wills/whosoever He wills.
The Women/4:105
We have sent down to you the Book containing the truth so that you may judge among your people as Allah has shown you. Do not side with the traitors.
The Table Spread/5:48
We have sent down to you this Book, which confirms the previous Books and replaces them, as a comprehensive truth, so judge between them by what Allah has sent down to you. Do not leave the truth that has come to you and follow their whim. We have appointed for each of you a law and a method, and if Allah had willed, He would have made you all one people. But He tests you with what He has given you. Compete in good deeds. To Allah is the return of all of you. He will inform you of the matters on which you differ.
The Table Spread/5:44
We sent down the Torah in which is guidance and light, and the Muslim prophets used to judge between the Jews by it. And the rabbis and the scribes used to judge by what they were commanded from the Book of Allah, and they were witnesses over it. Do not honor the people, honor Me, and do not sell My verses at a cheap price. Those who do not judge by what Allah has revealed are disbelievers.
The Table Spread/5:47
Let the people of the Gospel judge by what Allah has revealed in it. Whoever does not judge by what Allah has revealed, they are the transgressors.
The Arabic Letter Sad/38:26
O David, We have made you ruler over the earth. Judge between the people with justice, and do not be carried away by your desires and emotions, lest they lead you astray from the Way of Allah. Those who deviate from the way of Allah will have a severe punishment because they have forgotten the Day of Reckoning.