(The Impartial Judge)
The Arbitrator, The Judge, The Giver of Justice.
Allah is Al-Hakam (in Arabic: ٱلْحَكَمُ), The Giver of Justice. His judgment, once rendered, cannot be thwarted. He always delivers justly in every situation and never makes a mistake. He is the best of judges.
From the root ha-kaf-mim (ح ك م), which has the following classical Arabic connotations: to be wise, knowing the true nature of things, to pass judgment, to decide, pass a verdict, to judge and pass sentence, to prevent or restrain from wrongdoing or corruption, to turn someone back from wrongdoing or ignorance.
Al-Hakam is the judge, the arbitrator, and the giver of justice. Similar to Al-Hakeem (The All-Wise), which comes from the same root. To be the best of judges, you must be all-wise. You may hear the term Hikmah, a concept from Islamic philosophy that concerns wisdom, rationality, and objectivity, i.e., knowing the essence of things as they are. A person with hikmah has complete clarity. They see the action and the consequences thereafter.
Imam al-Ghazali writes, He "is the arbitrating magistrate and the avenging judge, whose ruling no-one overturns and whose decree no-one corrects."
Afahukmal jaahiliyyati yabghoon; wa man ahsanu minal laahi hukmal liqawminy yooqinoon (section 7)
"Then is it the judgement of [the time of] ignorance they desire? But who is better than Allah in judgement for a people who are certain [in faith]." — (Qur'an 5:50)
Innaa kulla shai’in khalaqnaahu bi qadar
"Verily, all things have We created in proportion and measure." — (Qur'an 54:49)
Allaahu yahkumu bainakum Yawmal Qiyaamati feemaa kuntum feehi takhtalifoon
"Allah will judge between you on the Day of Resurrection concerning that over which you used to differ." — (Qur'an 22:69)
Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ ruling:
An essential aspect of the name Al-Hakam is to help us understand the decree of Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ. Under the lens of Him being the most wise and the best of judges, we shouldn't worry ourselves with what has been decreed. The hadith mentions for us to "recognize and acknowledge Allah in times of ease and prosperity, and He will remember you in times of adversity. And know that what has passed you by [and you have failed to attain] was not going to befall you, and what has befallen you was not going to pass you by. And know that victory comes with patience, relief with affliction, and hardship with ease." 
Our only task in this life is to take control of our hearts' state, keep it pure despite the surrounding factors, and perform to the best of our abilities. We must find and focus our attention on the things which are within our control. Everything else that happens outside is the will of Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ, and He is the best arbitrator. If your focus is on things outside of your grasp, you will forever give up your happiness. Shaykh Tosun Bayrak says, "Instead of questioning Allah's judgment, be a true judge of yourself. Neither tyranize yourself nor excuse and pamper yourself." Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ says, "And that there is not for man except that [good] for which he strives And that his effort is going to be seen – Then he will be recompensed for it with the fullest recompense" (Qur'an 53:39-41)
Du'a of Prophet Muhammad ﷺ:
We can learn the same du'a for guidance that Prophet Muhammad ﷺ made as mentioned in the hadith which mentions Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ as the arbitrator:
Allahumma, rabba Jibra'ila, wa Mika'ila, wa Israfila Fatira s-samawati wa l-ardi, alima l-ghaybi wa sh-shahadati, anta tahkumu bayna ibadika fima kanu fihi yakhtalifuna. Ihdini li makhtulifa fihi min al-haqqi bi idhnika. Innaka tahdi man tasha'u ila siratin mustaqim.
"O Allah, Lord of Jibraīl, Mīkaīl and Israfīl (great angels), Creator of the heavens and the Earth, Knower of the seen and the unseen. You are the arbitrator between Your servants in that which they have disputed. Guide me to the truth by Your leave, in that which they have differed, for verily You guide whom You will to a straight path."
A believer benefits in knowing that Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is Al-Hakam. Although it can be difficult to find in your heart to forgive a perpetrator, personal retribution is not always necessary, knowing justice will be served on the day of judgment. This is not meant with any malice. Perhaps whatever the person did, he atoned sincerely, and Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ sees and knows best. But from an individual standpoint, if we understand and accept Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is Al-Hakam, it can be used as a tool to remain emotionally whole and to find forgiveness instead of seeking revenge.
We share a beautiful quote by the writer Cormac McCarthy on forgiveness, "He knew that our enemies by contrast seem always with us. The greater our hatred the more persistent the memory of them so that a truly terrible enemy becomes deathless. So that the man who has done you great injury or injustice makes himself a guest in your house forever. Perhaps only forgiveness can dislodge him." This is similar to the idea that hate is a poison more deadly to the hater than the hated.
Wattabi maa yoohaaa ilaika wasbir hattaa yahkumal laah; wa Huwa khairul haakimeen (section 11)
"And follow what is revealed to you, [O Muhammad], and be patient until Allah will judge. And He is the best of judges." — (Qur'an 10:109)
Another takeaway is we can strive to be impartial just as Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is impartial. It should increase our desire to raise our standards to be rational, objective, and righteous in our actions. To consistently make the right decision aligned with our values and deen.
Abdur-Rahman bin Abi Bakrah narrated: "My father wrote to 'Ubaidullah bin Abi Bakrah who was a judge: "Do not pass a judgement between two people while you are angry, for indeed I heard the Messenger of Allah (ﷺ) saying: 'The judge should not judge between two people while he is angry.'"