A prophet will the LORD thy God raise up unto thee, from the midst of thee, of thy brethren, like unto me; unto him ye shall hearken; —(Deuteronomy 18:15, OJPS)
God raised up many prophets. Not just a prophet. Is Moses talking about a unique super prophet or something?
So how come?
The text consistently uses a singular form when discussing a hypothetical, not to say that that hypothetical will happen on only one occasion but that the rule applies to whenever it happens. Devarim 24:1 speaks of finding a corpse, but does in the singular. This doesn't mean that it can only happen once. Even 18:10 which discusses the impermissibility of sorcerers says that A sorcerer should not be found among you. This doesn't mean that you must have more than one at a time for it to be OK. The use of the singular is to make a general case, not an exclusive moment. When Bamidbar 13 speaks of taking a man afflicted with tzara'at to THE kohen it does not mean that there will be only 1 kohen.
Note that the following verse also uses the singular noun. Note the use of the definitive article:
"But the prophet, that shall speak a word presumptuously in My name, which I have not commanded him to speak, or that shall speak in the name of other gods, that same prophet shall die.'"
See also Deut. 13:2 which also deals with a false prophet: "If there arise in the midst of thee a prophet..."
The language is the same. Here the same term for "arise/raise" is used.
Clearly, there were many false prophets, so obviously the verse is not talking about a singular definitive false prophet. It stands to reason that the early verses are also not exclusive to a single prophet. Indeed, these verses are the source for the commandment to listen to the words of a true prophet. Obviously, this commandment refers to all true prophets through history. For details of this commandment see Maimonide's Sefer HaMitzvot, Positive Command #172. The Chabad website provides a full English translation.
The significance of the phrase "God raise up" can be seen by reading Maimonides' explanation of prophecy in his Guide For The Perplexed, part II, chapter 32. He states that there are three opinions of how one achieves prophecy. The first opinion is that God chooses anyone He desires to be a prophet, even if that individual is a fool and not particularly pious. The second opinion is that anyone who studies and perfects his faculties will necessarily prophesize. Maimonides rejects both these opinions and maintains that only an individual who has prepared himself for prophecy and whom God chooses to inspire will prophesize. (That's it in a rather crude nutshell- please consult the Guide for the full treatment.) So the verse is telling us that not every wise and righteous individual will necessarily prophesize, it's only one who "God raises up" who shall deliver prophecy.
