A prophet from the seed of Ishmael is necessary to fufill Genesis 17:7?

Question

In Genesis 17:7 I will establish my covenant between me and you, and your offspring after you throughout their generations, for an everlasting covenant, to be God to you and to your offspring after you.

God the almighty promised Abraham that he will be God to his offspring, an everlasting covenant...

Some Muslims argue that such promise is a prophecy of the appearance of a prophet among the sons of Ishmael as it wasn't fully fulfilled till the appearance of Muhammad, as he is the one who made the the seed of Abraham, through his son Ishmael, know the God of Abraham.

Is this a valid argument?

Answer 1

Let's look at the verse

וַהֲקִמֹתִ֨י אֶת־בְּרִיתִ֜י בֵּינִ֣י וּבֵינֶ֗ךָ וּבֵ֨ין זַרְעֲךָ֧ אַחֲרֶ֛יךָ לְדֹרֹתָ֖ם לִבְרִ֣ית עוֹלָ֑ם לִהְי֤וֹת לְךָ֙ לֵֽאלֹהִ֔ים וּֽלְזַרְעֲךָ֖ אַחֲרֶֽיךָ

The promise is made to the זרע of Abraham. זרע literally means seed, but is often translated as offspring.

We find later on in Genesis Ch. 21 v. 12 that Sarah demands that Yishmael be sent away. G-d tells Abraham to do so, saying,

וַיֹּ֨אמֶר אֱלֹהִ֜ים אֶל־אַבְרָהָ֗ם אַל־יֵרַ֤ע בְּעֵינֶ֙יךָ֙ עַל־הַנַּ֣עַר וְעַל־אֲמָתֶ֔ךָ כֹּל֩ אֲשֶׁ֨ר תֹּאמַ֥ר אֵלֶ֛יךָ שָׂרָ֖ה שְׁמַ֣ע בְּקֹלָ֑הּ כִּ֣י בְיִצְחָ֔ק יִקָּרֵ֥א לְךָ֖ זָֽרַע׃
But God said to Abraham, “Do not be distressed over the boy or your slave; whatever Sarah tells you, do as she says, for it is through Isaac that offspring shall be continued for you.

In other words, the title of זרע or "seed" of Abraham only applies to the descendants of Isaac, and not the descendants of Yishmael. So even though descendants of Yishmael are technically his offspring (as we see in the next verse), they do not have the official title of offspring. As such, the promises made to Abraham's offspring in Genesis 17 do not apply to them.