Genesis 24:3 - Matthew Poole's English Annotations on the Holy Bible

i.e. Not persuade nor engage my son to take; for Isaac, though forty years old, was not only willing to be governed by his father in this affair, but also to hearken to the counsel of this wise and faithful servant, of whom both his father and himself had such long and large experience. He knew that the Canaanites were not only gross idolaters and heinous sinners, for so many others were; but that they were a people under God's peculiar curse, Genesis 9:25, and devoted to extirpation and utter destruction, which was to be inflicted upon them by Abraham's posterity; and therefore to marry his son to such persons had been a high degree of self-murder, whereby the holy and blessed seed had been in danger of great infection from them, and utter ruin with them. And Abraham's practice was afterwards justified by God, who hath oft showed his dislike of such unequal matches of his people with those infidels and idolaters, by severe prohibitions and sharp censures. See Exodus 34:16 Deuteronomy 7:3 Joshua 23:12 Ezra 9:1-3 Nehemiah 13:23,25 2 Corinthians 6:14,15.