Why didn’t Abraham protest when he was told to sacrifice Isaac, when he did protest about the destruction of possible righteous people in Sodom?
1) For a (relatively) disinterested person to protest against possible injustice is one thing; to disobey or protest a direct Divine order is quite another thing. 2) In the Talmud Yerushalmi (Taanis 2:4) and in many Midrashim, Abraham is quoted as saying to G-d (afterwards) that he could have protested when he was told to offer Isaac as a sacrifice, since G-d had promised him descendants through Isaac, but he suppressed his feelings and didn’t protest. 3) Many commentators and Midrashim point out that G-d didn’t explicitly tell Abraham to sacrifice Isaac, but only to “raise him up” as an offering. True, Abraham brought wood, fire, and a knife to the mountain, but he may have believed that G-d would provide an animal to be sacrificed; indeed, this is what he told Isaac on the way up the mountain, and this is what actually happened.