"Dread the day wherein one soul shall not make satisfaction for another soul, neither shall any intercession be accepted from them, nor shall any compensation be received, neither shall they be helped." (2: 48)
Quoting this verse, the writer argues about the Muslim belief that The Prophet would intercede for them on the day of judgment. The answer is simple and in the introduction of this article. The rules of context has the answer for it. Many a times we see repetition in the Quran. Upon a closer look, we see that there is no complete repetition and each time something is repeated, there is new information with it as well. This is the style of the Quran and when we see this same message being repeated, we see that there is no problem at all. The writer should have consulted a knowledgeable Muslim before writing this chapter of his book.
[053:026] There are many angels in the heavens. But their intercessions would not help anyone a bit, unless Allah allows such specific mediation in favor of whomever He wills, and pleases.
[020:109] On that Day shall no intercession avail except for those for whom permission has been granted by (God) Most Gracious and whose word is acceptable to Him.