Or HaChaim on Genesis 24:23/אור החיים על בראשית כ״ד:כ״ג

1 בת מי את, הגידי, "Whose daughter are you? Tell me, etc." The Torah lumps both these questions together to show that Eliezer did not entertain any doubts that the girl must belong to Abraham's family. Had he entertained such doubts he could not have enquired immediately about the chance of lodging in her parents' home until he had clarified who her parents were. He merely wanted to know her father's name. He added his enquiry about staying at her parents' overnight to emphasise that this had nothing to do with her father's name, that he was convinced G'd had guided him to the right family.