13. upon … mountains—High places were selected by idolaters on which to sacrifice, because of their greater nearness to the heavenly hosts which they worshipped (De 12:2).
elms—rather, "terebinths" [Maurer].
shadow … good—screening the lascivious worshippers from the heat of the sun.
daughters … commit whoredom … spouses … adultery—in the polluted worship of Astarte, the Phœnician goddess of love.