The Meaning of the Statement of Allah the Exalted: {That You Judge Between the People by What Allah Has Shown You}

Q: Allah the Exalted said: [Al-Nisa: 105]. Does this mean that Allah commanded His Messenger (peace and blessings be upon him) to judge by the Book of Allah and not to exercise independent legal reasoning in matters for which no Book was revealed to him? Did the Messenger of Allah (peace and blessings be upon him) exercise independent legal reasoning?
A: Allah (Mighty and Majestic) commanded His Messenger (peace and blessings be upon him) to judge between people by what Allah revealed to him. He, the Exalted, said: [Al-Ma'idah: 49]. So he judged by what Allah had revealed. If there was no explicit text with him, he (peace and blessings be upon him) would exercise independent legal reasoning and judge by the evidence of the Shari'ah that he had, as he said in the authentic hadith: It is agreed upon as authentic from the hadith of Umm Salama (may Allah be pleased with her).
The meaning of this is that he may exercise independent legal reasoning in judgment according to the rules of the Shari'ah, because nothing was revealed to him regarding it. Whoever knows that the judgment is not in accordance with the truth and that the witnesses are false has taken a piece of the Fire, so let him beware of that and fear Allah in himself, even if the Messenger (peace and blessings be upon him) is the judge over him. This is because the judge has only the apparent truth from the trustworthiness and justice of the witnesses, or the oath of the defendant. If the claimant presents witnesses whom he knows have erred, even if they are pious, and that the right is not his, or if he knows they are false witnesses but the judge considers them just because they are just in his estimation and he has certified them, then this wealth that is judged for him, or the retaliation, is entirely invalid for him because of his knowledge of its invalidity. He has transgressed the limits of Allah and committed injustice, even if the judge ruled in his favor, because the judge has only the apparent truth. For this reason, he (peace and blessings be upon him) said: .
The Prophet (peace and blessings be upon him) judges by what Allah revealed in what Allah inspired to him, and in matters where there is no explicit text, he (peace and blessings be upon him) exercised independent legal reasoning so that the community would follow his example. In all of this, he is considered to be judging by what Allah revealed, because he judged by the rules of the Shari'ah that Allah commanded him to judge by. For this reason, he said to al-Zubayr ibn al-Awwam (may Allah be pleased with him) when he claimed against a person regarding a piece of land: . Al-Zubayr said: "If so, he will swear, O Messenger of Allah, and not care." The Prophet (peace and blessings be upon him) said to him: It is agreed upon.
When he sent Mu'adh as a delegate to Yemen, he said to him: ? He said: "I will judge by the Book of Allah." He said: . He said: "Then the Sunnah of the Messenger of Allah (peace and blessings be upon him)." He said: . He said: "I will exercise independent legal reasoning and not spare any effort." He (peace and blessings be upon him) struck him on his chest and said: . It was narrated by Imam Ahmad and a group with a good chain of narration.