What does the word "fataḥa" (lit. 'opened') mean here?

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

1. It means "that which Allah has decreed for you," and (fatḥ) means "decree", as in the verse "Our Lord, decide (iftaḥ) between us and our people in truth." (7:89). Al-Suddī narrated from his teachers: Some of the Jews believed and then became hypocrites, and they would tell the believers about the punishment they had received. Some of them said to others: "Do you tell them what Allah has decreed for you?"
2. It means "that which Allah has taught you". Ibn ʿAbbās, Abū al-ʿĀliyah, and Qatādah said, "What Allah has disclosed to them is what He revealed in the Torah about the description of Muḥammad (ﷺ)."

Muqātil said: A Muslim would meet his ally or his foster brother from the Jews and ask him: "Do you find Muḥammad in your book?" They would say: "Yes, it is the truth." When Kaʿb ibn al-Ashraf and others heard this, they said to the Jews secretly: "Do you tell Muḥammad's companions what Allah has disclosed to you in the Torah about Muḥammad, so they can use it as evidence against you before your Lord by your admission that he is a prophet? Do you not understand that this is a proof against you?"