3) God Will Put His Words in the Mouth of this Prophet
The words of Allah (the Holy Quran) were truly put into Muhammad’s [pbuh] mouth. God sent the angel Gabriel to teach Muhammad [pbuh] the exact words of god (the Holy Quran) and asked him to dictate them to the people as he heard them. The words are therefore not his own. They did not come from his own thoughts, but were put into his mouth by the angel Gabriel. During the life time of Muhammad [pbuh], and under his supervision, these words were then memorized and written by his companions.
Also, this prophecy in Deuteronomy mentioned that this prophet will speak the words of god in the name of god. If we looked to the Holy Quran, we will find that all its chapters, except Chapter 9, are preceded or begin with the phrase, “In the name of Allah, the Most Gracious, the Most Merciful.”
Another indication (other than the prophecy in Deuteronomy) is that Isaiah ties the messenger connected with Kedar with a new song (a scripture in a new language) to be sung to the Lord (Isaiah 42:10-11). This is mentioned more clearly in the prophecy of Isaiah: “and another tongue, will he speak to this people” (Isaiah 28:11 -kjv).
Another related point, is that the Quran was revealed in sections over a span of twenty-three years. It is interesting to compare this with Isaiah 28 which speaks of the same thing, “for it is: do and do, do and do, rule on rule, rule on rule; a little here, a little there.” (Isaiah 28:10).
Note that God has said in the prophecy of Deuteronomy 18, “if anyone does not listen to my words that the prophet speaks in my name, i myself will call him to account.” (Deuteronomy, 18:19). This means that whoever believes in the bible must believe in what this prophet says, and this prophet is the prophet Muhammad [pbuh].