Sforno on Leviticus 18:21/ספורנו על ויקרא י״ח:כ״א

1ומזרעך לא תתן להעביר למולך ולא תחלל את שם אלוקיך, the difference between offering sacrifices to the Moloch and to G’d respectively is that to G’d only animals are sacrificed, whereas to the deity known as Moloch, human beings, specifically one’s son, is sacrificed. This would indicate that the worshipper of the Moloch considers him as more powerful than G’d, for why else would he sacrifice his dearest possession, his son, to him and not to G’d?

2'אני ה, I have never changed since the time I have sworn to Avraham “to be your G’d and for seed after you.” (Genesis 17,7). Seeing that G’d in this chapter had spoken about incest, matters related to human seed, and His interest in keeping this seed pure so that the holy spirit would be able to descend upon such people, He spoke about the Moloch whose servants had intended to ensure that their other children would be blessed with every kind of success in recognition of their having given the oldest to their G’d. G’d is on record here that doing something like this, far from being a way to sanctifying G’d’s name would be the most potent way to desecrating His name. Such practices, far from attracting the benevolent presence of G’d, the Shechinah, would prevent this presence of G’d from taking up residence among the Jewish people..