God didn’t order Abraham to sacrifice his son!
“(Abraham) said: “O my son, I see in my dream that I am sacrificing you; so look what do you think.” (The Quran, as-Saffat  102).
According to the traditional expression God ordered Abraham to sacrifice his son to test him. However, such an order doesn’t take part in the Quran, but in the Old Testament: “…Sacrifice him there as a burnt offering on a mountain I will show you.” (Old Testament, Genesis 22:1-2).
There were human sacrifices in the days of Abraham. Abraham perceived his dream as an order and tried to make it real (The Quran, as-Saffat  105). He asked his son for his opinion, “what do you think?” shows that this was an interpretation about his behaviour. If it had been an order from Allah, he wouldn’t have asked his son whether to do it or not. If this were a clear order from Allah, he would have definitely had to do it. Additionally, this verse shows not to trust and deal with dreams.
Therefore, the order to sacrifice his son exists in the Old Testament, but not in the Quran.