7:42 gave them up. Compare Romans 1:24,26,28. Just as God had “given up” the ancient civilizations when they gave Him up for false gods, so He did with His chosen people when they lapsed into idolatry.
7:42 host of heaven. The “host of heaven” was the array of false gods (actually “fallen angels”) believed to dwell in the heavens, associated with the stars and the practice of astrology.
7:42 book of the prophets. See Amos 5:25-27. The ultimate result of their apostasy was exile beyond Damascus into Assyria, Babylonia and Persia.