And believe in what I have sent down (this Quran), confirming that which is with you, [the Taurat (Torah) and the Injeel (gospel)], and be not the first to disbelieve therein, and buy not with My Verses [the Taurat (Torah) and the Injeel (gospel)] a small price (i.e. getting a small gain by selling My Verses), and fear Me and Me Alone. (Tafsir At-Tabari, Vol. I, Page 253).

So if you (O Muhammad ﷺ) are in doubt concerning that which We have revealed unto you, [i.e. that your name is written in the Taurat (Torah) and the Injeel (gospel)] then ask those who are reading the Book [the Taurat (Torah) and the Injeel (gospel)] before you. Verily, the truth has come to you from your Lord. So be not of those who doubt (it).

These are the Verses of the manifest Book [this Quran, which was promised by Allah in the Taurat (Torah) and the Injeel (gospel), makes things clear].

And verily, it (the Quran, and its revelation to Prophet Muhammad ﷺ) is (announced) in the Scriptures [i.e. the Taurat (Torah) and the Injeel (gospel)] of former people.

Those to whom We gave the Scripture [i.e. the Taurat (Torah) and the Injeel (gospel), etc.] before it, - they believe in it (the Quran).