Isaiah 57:7

“Upon a lofty and high mountain hast thou set thy bed, &c.] Temples and altars, which are usually built on high places, where they commit spiritual adultery; that is, idolatry, in imitation of the Heathens, who had their temples and altars on high places; and the idolatry of the church of Rome, in this context, is all along expressed in language agreeable to the Heathen idolatry, and in allusion to it. Some think this phrase denotes impudence in their idolatrous worship; for not content to worship under trees, in valleys, and under clifts of rocks, and such dark places; now, as not blushing at, or being ashamed of their actions, erect their altars in the most public places. Perhaps some…”

“Upon . . . high mountain . . . bed--image from adultery, open and shameless (Eze 23:7); the "bed" answers to the idolatrous altar, the scene of their spiritual unfaithfulness to their divine husband (Eze 16:16, Eze 16:25; Eze 23:41).”

“Upon a lofty and high mountain - The design of this verse and the following, is, to show the extent, the prevalence, the publicity, and the grossness of their idolatry. The language is that which would appropriately express adulterous intercourse, and is designed to show the abhorrence in which God held their conduct. The language is easy to be understood, and it would not be proper to go into an extended explanation of the phrases used. It is common in the Scriptures to compare idolatry among the people of God, with unfaithfulness to the marriage vow. The declaration that they had placed their bed on a high mountain, means, that in the rites of idolatrous worship, there was no concealment.…”

“Mountain - In high places, which were much used for religious worship, both by Israelites and by Heathens. Thy bed - Thine altar, in which thou didst commit spiritual whoredom with idols. Isaiah 57:8”

“Jer 2:20, Jer 3:2; Eze 16:16, Eze 16:25, Eze 20:28, Eze 20:29, Eze 23:17, Eze 23:41 Isaiah 57:8”

“The prophet now proceeds with perfects, like שׁפכתּ and העלית (addressed to the national community generally, the congregation regarded as a woman). The description is mostly retrospective. "Upon a lofty and high mountain hast thou set up thy bed; thou also ascendedst thither to offer slain offerings. And behind the door and the post thou didst place thy reminder: for thou uncoveredst away from me, and ascendedst; thou madest thy bed broad, and didst stipulate for thyself what they had to do: thou lovedst their lying with thee; thou sawest their manhood." The lovers that she sought for herself are the gods of the heathen. Upon lofty mountains, where they are generally worshipped, did she set…”