1. The Prophecy
Deuteronomy 18:15 is just one verse from an entire chapter, one in which God pronounces his promise to the Israelites (and Moses) of sending intermediaries for them; for communication between them and God. But what is interesting is that Muslims would choose to ingore the entire chapter, and focus solely on that one word, to try to make their case.
If we look at the prophecy, we will find that at no point, would the term mean anything other than tribes men from the same Israelites. I would like to direct your attention to two other phrases used in that verse: from the midst of thee ('from among you') and 'like unto me.'
FROM THE MIDST OF THEE -- Who does this refer to? It is agreed by both sides, that this passage is referring to the Isrealites, for God is directing his speech towards them, through his servant Moses. So, now, we must determine what is the proper application of this particular phrase. The phrase indicates that God's promise will come from 'the midst' or from 'within' the people to whom he is pronouncing the prophecy. This could not possibly be applied to a group of people who aren't even part of the tribes of Israel. The promise must be from within the tribes, from their midst.
LIKE UNTO ME -- Who is this speaking? This is Moses, declaring God's promise to the Israelites. Now, this particular passage is subject to much discussion, and people always start drawing comparisons between their favorite characters, to show how they are so alike. But not once have I seen someone bring to the table the most important of all these comparisons, the heritage of the character -- Moses was an Israelite! Many like to think of the word "like me" as a type of character, personality, attitude, etc. But the fact is, that is not what Moses is speaking of, when he states that the prophets are going to be like him. Let me show a crucial part of this speech:
From the midst of thee, of thy brethren, like unto me.
Can Moses be any clearer? God will raise someone, just as he did with Moses, from the midst of the Israelites. It is clear, Moses was an Israelite, so the prophets were going to be Israelites, as well. There is no way to get around this fact, and it is evident that all the prophets in Israel were from among the descendants of Israel -- and this includes The Prophet who would conclude the line of prophets sent to Israel.
As I satated earlier, this is but one passage in the entire chapter, and anyone reading the chapter will immediately realize that the idea that brethren would be interpreted in such manner would be rediculous, especially since all over the place the word is used to indicate the tribes of Israel. One passage I would like to show is the first two verses of the chapter:
The priests the Levites, [and] all the tribe of Levi, shall have no part nor inheritance with Israel: they shall eat the offerings of the LORD made by fire, and his inheritance. Therefore shall they have no inheritance among their brethren: the LORD [is] their inheritance, as he hath said unto them. (Deut 18:1-2)
Clearly, here the term is used to indicate the tribes of Israel.
--CONTINUED BELOW