Q: Allah (Exalted be He) says: that you might judge between men by that which Allâh has shown you (i.e. has taught you through Divine Revelation) Does this mean that Allah has commanded His Messenger (peace be upon him) to judge according to the rulings embedded in the Qur'an without exerting any personal effort pertaining to matters that have no text? Did the Messenger of Allah (peace be upon him) ever practice Ijtihad (juristic effort to infer expert legal rulings)?
A: Allah (Glorified and Exalted be He) has commanded His Messenger (peace be upon him) to judge among people according to what has been revealed to him. Allah (Exalted be He) says: And so judge (you O Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ) among them by what Allâh has revealed He (peace be upon him) used to judge according to what Allah (Exalted be He) revealed and when there was no text, he practiced Ijtihad and depended on evidence from Shari`ah (Islamic law). It is confirmed that the Prophet (peace be upon him) said, "You people present your cases to me and some of you may be more eloquent and persuasive in presenting their argument than others. If, as a result, I give someone's right to another, I am in fact giving them a piece of the Fire. They can either take it or leave it." (Agreed upon by AlBukhari and Muslimand it was related on the authority of Um Salamah, may Allah be pleased with her). The Hadith means that the Prophet (peace be upon him) could practice Ijtihad in judgments based on Shari`ah when there was no evidence revealed regarding them. Anyone who knew the judgment was not based on the truth and had presented false witnesses had indeed taken a piece of the Fire. They should beware of that and fear Allah, even if the judge was the Messenger of Allah (peace be upon him).
This is because a judge depends on what is known of the trustworthiness and uprightness of the witness or of the claimant's oath. So the claimant may bring false witnesses known to be trustworthy while he has no right, or he may know they are false witnesses while the judge considers them to be upright, for they fulfill the formal requirements of uprightness. In this case, the money, disputed item or the Qisas (retaliation), are not the claimant's right since he knows it is not and knows that he has transgressed and wronged the other. The right will not be lawful for the plaintiff even if the judge gives it to him, for a judge can only judges according to the facts and evidence presented. That is why the Prophet (peace be upon him) said, "If, as a result, I give someone's right to another, I am in fact giving them a piece of the Fire." Therefore, the Prophet (peace be upon him) judged according to what Allah revealed to him and whenever a matter had no revealed text, he practiced Ijtihad, for his nation to follow his example. In both cases, the judgment is according to what Allah has revealed, as he is applying
Shari`ah which Allah (Exalted be He) has revealed. Thus, when AlZubayr ibn Al`Awwam (may Allah be pleased with him) complained that someone took a piece of his land, the Prophet (peace be upon him) said, "Present your two witnesses or he will take his oath.' So AlZubayr said, 'Then he will take a false oath caring for nothing?' The Prophet (peace be upon him) said, 'You have nothing but that.'" (Agreed upon by AlBukhari and Muslim).
"When the Prophet (peace be upon him) sent Mu`adh as his delegate to Yemen, he asked him, 'How will you judge in cases presented to you?' He said, 'I will judge according to what is revealed in the Qur'an.' He (peace be upon him) asked, 'What if you do not find it in the Qur'an?' He said, 'I will judge according to what is in the Sunnah (whatever is reported from the Prophet).' He (peace be upon him) asked, 'What if you do not find it in the Sunnah?' He said, 'I will practice Ijtihad and will spare no effort.' Upon hearing that, the Prophet (peace be upon him) tapped him on the chest and said, 'All praise be to Allah Who has granted the Messenger of Allah success to find what pleases the Messenger of Allah.'" (Related by Ahmad and others with a good chain of narrators).