The legislation of those before us in the rulings of the Shari'ah

Question:
Honorable Shaykh, is the legislation of those before us a proof in the rulings of the Shari'ah, as in the story of Musa (peace be upon him)?

Answer:
If the legislation of those before us is mentioned, they say it falls into three categories. The first category is what our Shari'ah has come with in opposition to it; this is not a Shari'ah for us, and this is by consensus. The second category is what our Shari'ah has come with in agreement with it; this is a Shari'ah for us by consensus. The third category is what our Shari'ah has not come with in opposition to it nor in agreement with it; this is a matter of disagreement among the scholars, and the correct view is that it is not a Shari'ah for us.
And the story of Musa (peace be upon him) is one where our Shari'ah has come in agreement with it, by legislating the wage, by legislating that the benefit be made a bridal gift, just as the Prophet (peace and blessings be upon him) did with the one you heard about, marrying her with what you have of the Qur'an. The Messenger made the benefit, which is teaching her the Qur'an, a bridal gift, exactly as Musa (peace and blessings be upon him) did.