4. They were at great expense with their idolatry, and laid out a great deal of wealth in purchasing patterns of images and altars, and hiring priests to attend upon them from other countries. Harlots generally had their hire; but this impudent adulteress, instead of being hired to serve idols, hired idols to protect her and accept her homage. This is much insisted on, v. 31-34. "In this respect the contrary is in thee from other women in thy whoredoms: others are courted, but thou makest court to those that do not follow thee, art fond of making leagues and alliances with those heathen nations that despise thee; others have gifts given them, but thou givest thy gifts, the gifts which God had graciously given thee, to thy idols; herein thou art like a wife that commits adultery, not for gain, as harlots do, but entirely for the sin's sake." Note, Spiritual lusts, those of the mind, such as theirs after idols were, are often as strong and impetuous as any carnal lusts are. And it is a great aggravation of sin when men are their own tempters, and, instead of proposing to themselves any worldly advantage by their sin, are at great expense with it; such are transgressors without cause (Ps. xxv. 3), wicked transgressors indeed.