Did he regard the opinions of the exegetes, such as Ibn Katheer and Ash-Sha`raawi? They all said the verse speaks of the Quran abrogating the Torah, and that this was the circumstance of revelation.
It surprises me that he would not call previous revelations signs (آيات). We showed earlier in this topic how many things God said were signs of His. How can a holy scripture He revealed be excluded from the list of signs?
The answer to the first question is that he did not cite Ibn Katheer explicitly in this instance, or Ash-Sha`raawi at all (he predated Ash-Sha`raawi or at least his fame). He did not mention the use of 2:105
as a preamble to interpreting 2:106 as addressing abrogation of previous books, period. He argued only that 2:105 was about the enemies of Islam, and that the link to 2:106 was that 2:106 addressed Quranic abrogation which is a subject of attack by the enemies of Islam. It looked like he was avoiding 'the elephant in the room'.
The answer to the second question is that his sole argument was the absence of such definition from Arabic dictionaries. It sounded like going overboard with excluding previous holy books, as it is conceivable that 2:106 is talking about both the Quran
and previous holy books, which can still accommodate the abrogation doctrine, but he seemed keen on excluding even
the possibility of previous holy books.