There were two covenant mentioned when God said:
 And my covenant will I establish with Isaac, which Sarah shall bear unto thee at this set time in the next year.
These are, firstly, the covenant that say: For god to be their god and all the land of Canaan will be their inheritance. Secondly, the covenant of circumcision.
I believe the covenant of circumcision was meant for Ishmael likewise as he was circumcised. So on the context of objectivity, which covenant was promised to Isaac? Was it the first or the second?
We can say, the covenant of circumcision was for ishmael likewise but the first covenant specified could only be for isaac.
And I will establish my covenant between me and thee and thy seed after thee in their generations for an everlasting covenant, to be a God unto thee, and to thy seed after thee.
And I will give unto thee, and to thy seed after thee, the land wherein thou art a stranger, all the land of Canaan, for an everlasting possession; and I will be their God.
That covenant is specifically for Isaac as by saying:
And my covenant will I establish with Isaac
It could only be for Isaac as realized when his seed–the israelites–settled in all the land of Canaan as specified in Numbers 34. Below is the illustration of that promised settlements for the twelve tribes–all the land of canaan:
So on the context of objectivity, we could say, that the promised covenant established with isaac was the one saying, FOR GOD TO BE YOUR GOD AND FOR ALL CANAAN TO BE YOUR INHERITANCE, as indeed all the land of Canaan was given to his seed. Meaning, isaac and his seed was promised a rather godly state wherein personally, they were chosen as a people having divine authority over them, that is, for god to be their god.
Could such covenant be merited to for Ishmael and his arab descendants, for god to be their god, in their collective state?
Biblically, No. As Ishmael’s progeny–Muslims–inherits his character, a wild man, so as specified in Gen 16:12.
How are Muslims a wild man?
The world being dominated by Islam, meaning, many countries would be Islamic, would war against God as it say:
Behold, the day of the LORD cometh, and thy spoil shall be divided in the midst of thee.
For I will gather all nations against Jerusalem to battle; and the city shall be taken, and the houses rifled, and the women ravished; and half of the city shall go forth into captivity, and the residue of the people shall not be cut off from the city.
Then shall the LORD go forth, and fight against those nations, as when he fought in the day of battle.
So on that note, being in war against God, these islamic countries represents islam as by the notion, islam would dominates the world, therefore islam wars against god making it impossible to think that Ishmael and his seed had ever a covenant for god to be their god. It could only be for Isaac.
Also, specifics in history–the compilation of biblical manuscripts–was supported by the notion that one collective writing of god would be gathered when it say:
Seek ye out of the SEPHER (WRITING) of the LORD, and read: no one of these shall fail, none shall want her REUTH (ADDITIONAL ONE): for my mouth it hath commanded, and his spirit it hath gathered them.
It was never implied, that that is the Quran as it needs additional ones such as the hadith’s, gospel and Torah so as it specified.
“But when the truth has come to them from Us, they say: `why is he not given the like of what was given to Moses?’ Did they not disbelieve in that which was given to Moses before? They say: `Two kinds of magic (the Torah and the Quran) each helping the other!‘ And they say: `Verily! In both we are disbelievers.’ Say (to them, O Muhammad): `Then bring a Book from Allah, which is a better guide than these TWO (the Torah and the Quran), that I may follow it, if you are truthful.'”
Sahih International: O you who have believed, believe in Allah and His Messenger and the Book that He sent down upon His Messenger and the Scripture which He sent down before. And whoever disbelieves in Allah , His angels, His books, His messengers, and the Last Day has certainly gone far astray.
Therefore, only the biblical manuscripts fit this prophecy as the writing of the lord.
Would this writing be corrupted or lost?
Impossible. Bec it was promised: no one of these shall fail. So on that context, Quran cannot be the writing of god as this particular writing of god would exist and never fail. Meaning, this writing of god would coexist with quran as it won’t fail yet it dont need quran as by saying: none shall want additional one.
This writing of god was meant for all generation to come thus it cannot be corrupted:
But thou, O LORD, shalt endure for ever; and thy remembrance unto all generations.
This shall be written for the generation to come: and the people which shall be created shall praise the LORD.
Lastly, everything about life and godliness was already given, implying, everything about salvation was given therefore what need is there for Islam? It proves by this fact that Islam is falsehood.
2 Peter 1:3
According as his divine power hath given unto us all things that pertain unto life and godliness, through the knowledge of him that hath called us to glory and virtue:
So without any incoherence, there could not have been any possibility of any covenant in this aspect: for god to be their god, that was established with ishmael seeing that firstly, ishmael’s progeny–muslims–would war against god. Secondly, Quran is not the writing of god therefore as a foundation, its basically falsehood. Lastly, everything about salvation was already complete before Islam thus making Islam false.
It only corroborated one thing. The covenant established with isaac therefore was for god to be their god, meaning, religion of god would emerge from this lineage and not from Ishmael.