I don’t know why you need to find that specific sentence, since it supports everything else we’ve been saying. You can’t treat a margin loan used to buy a house as investment interest, because it is not investment property. But that is not the same thing as saying that you can use it as home mortgage interest instead, because it doesn’t fit the rules for that deduction. (Margin loan interest used to buy a home does not fit the rules for any interest deduction.)
