Genesis 22: 2: And he said, Take now thy son, thine only son Isaac, whom thou lovest, and get thee into the land of Moriah; and offer him there for a burnt offering upon one of the mountains which I will tell thee of.
Abraham had two sons, the first was Ishmael, and the second was Isaac. Ishmael is believed by the Muslims to be the ancestor of their prophet Muhammad, and the Arab Muslims trace their lineage all the way back to Ishmael. There is however a small miscalculation that the religion of Islam has not factored in, and it is that when God told Abraham to take Isaac up into the mountains of Moriah to be sacrificed, He referred to Isaac as being Abraham’s only son.
In Genesis 16: 15 we read: And Hagar bare Abram a son: and Abram called his son’s name, which Hagar bare, Ishmael. Here we can clearly see that Ishmael was the firstborn son of Abram, whereas Isaac is the firstborn son of Abraham, for when Ishmael was born, Abram had not yet had his name changed to Abraham. Abraham was given his new name in Genesis 17: 5: Neither shall thy name any more be called Abram, but thy name shall be Abraham; for a father of many nations have I made thee. So for the Muslims and the entire Islamic faith who trace their ancestry and roots all the way back to Ishmael, they actually have no connection to Abraham whatsoever, for Ishmael is not recognized by God as being the son of Abraham.