What is meant by "al-furqān" in this āyah?

Imām Ibn al-Jawzī (d. 597/1201) summarized the scholars' opinions in his book "Zād al-Masīr" as follows:

1. It means victory. [Ibn ʿAbbās, Ibn Zayd]
2. It refers to the teachings of the Torah which differentiate truth from falsehood: Thus, al-Furqān would be a description of the Torah. [Abū al-ʿĀliyah]
3. It means the Book, therefore it is referring to the same thing but with a different word (for emphasis). [Mujāhid, al-Farrāʾ, al-Zajjāj]
4. It refers to the parting of the sea for them. [Al-Farrāʾ, al-Zajjāj, Ibn al-Qāsim al-Anbārī]
5. It refers to the Qurʾān: The meaning of the verse would then be: "We gave Moses the Book, and Muḥammad the Furqān." [Quṭrub; mentioned by al-Farrāʾ]