Is the intent behind the phrase "in it are pairs from every book" in the example of the necessity of intention when seeking knowledge, that one of the two books is free of innovations and the other contains them, or that both books are sound?

Perhaps the Sheikh means that these books are rich in knowledge, borrowing the Quranic phrase describing the two gardens: "In them are two of every fruit." The intent is that these books are not sufficient to refute the innovators; rather, scholars are needed to debate them and defend the Sharia.