ksazma, perhaps you failed to understand the Bible and Quran, Abraham had obeyed God many times in his walk with Him, but no test could have been more severe than the one in Genesis 22. God commanded, "Take your son, your only son, Isaac, whom you love, and go to the region of Moriah. Sacrifice him there as a burnt offering" (Genesis 22:2). I understand that the Quran didn't say who was being sacrifice, we will get to that later to clear up your misunderstand.
Since this idea steam from ksazma misunderstanding of the phrase "only son", it becomes necessary to explain what this phrase exactly means in relation to Isaac. A careful reading of the Bible shows that the phrase is used to affirm Isaac's unique status, a status based on the following,
1 - Isaac was the promised child of Abraham, a fact which the Quran agrees with Genesis 17:15-21; Surah 11:69-73, 37:112-113, 51:24-30), pay attention to Surah 11:71 .
2 - Isaac was conceived miraculously to a barren mother and a very aged father, the Quran likewise agreeing with Genesis 17:15-17, 18:9-15, 21:1-7; Galatians 4:28-29; Surah 11:69-73, 51:24-30
3 - In Genesis 13:14-18, 15:18-21, 28:13-14 God promised that it would be Isaac's descendants who would inherit the land given to Abraham. Ishmael had no part in the inheritance and promise given to Isaac through Abraham.
It is for these reasons that Isaac is called Abraham's only son since God himself reckoned him as the child of promise and blessings, an honor never bestowed upon Ishmael.
Even more startling is the fact that the Quran never mentions the name of the sacrificial child; amazing indeed considering how ksazma overzealous stated, as I quote him, "...at the time that Abraham was going to sacrifice ISHMAEL, Isaac was not even conceived..."
Lets read Surah 37:99-106: "And [then] he said, "Indeed, I will go to [where I am ordered by] my Lord; He will guide me. My Lord, grant me [a child] from among the righteous." So We gave him good tidings of a forbearing boy.
"And when he reached with him [the age of] exertion, he said, "O my son, indeed I have seen in a dream that I [must] sacrifice you, so see what you think." He said, "O my father, do as you are commanded. You will find me, if Allah wills, of the steadfast."’
"And when they had both submitted and he put him down upon his forehead, we called out to him, ‘O Abraham! You have fulfilled the vision." Indeed, We thus reward the doers of good Indeed, this was the clear trial" (Surah 37:99-106).
Hmm, ksazma quote, "God never told Abraham to sacrifice anyone", you should read Surah 11:71 again.
I recall an Islamic historian by the of Al-Tabari, do you know him ksazma? he said, and I quote, "The earliest sages of our Prophet's nation disagree about which of Abraham's two sons it was that he was commanded to sacrifice. Some say it was Isaac, while others say it was Ishmael. Both views are supported by statements related on the authority of the Messenger of God. If both groups of statements were equally sound, then - since they both came from the Prophet only the Quran could serve as proof that the account naming Isaac is clearly the more truthful of the two."