What is the legal authority of the law of those before us?

Scholars have differed regarding the validity of using the previous revelations as proof. Some jurists hold that it is not a proof, citing the Almighty's saying: ﴿To each among you have We prescribed a law and a clear way﴾, and the Prophet's (peace be upon him) saying: "A prophet was sent to his own people specifically, and I was sent to all mankind."

The majority, however, assert that it is a proof, citing the Almighty's saying: ﴿Those were the ones whom Allah guided. So follow their guidance﴾, and the hadith of Al-Rabee' bint An-Nadr, who broke a woman's tooth. The Messenger of Allah (peace be upon him) commanded retaliation (qisas). Anas ibn An-Nadr then said: "O Messenger of Allah, do not break her tooth!" The Prophet (peace be upon him) said: "O Anas, the Book of Allah dictates retribution (qisas)." So they reconciled and pardoned. What is in the Book of Allah the Almighty is what Allah decreed in the Torah: ﴿And We ordained for them therein a life for a life, an eye for an eye, a nose for a nose, an ear for an ear, a tooth for a tooth, and for wounds is retribution﴾.

Some scholars adopted a detailed approach, stating: the law of Abraham and whatever from the laws of the prophets is mentioned in the Qur'an and Sunnah with praise, affirmation, or silence without opposition, is a proof that must be followed; for the Almighty's saying: ﴿Then We revealed to you, [O Muhammad], to follow the religion of Abraham, inclining to truth﴾.

The preponderant opinion is that of the majority, which is that the law of those before us is a law for us, as long as there is nothing in our law that contradicts it.