Rabbi Meir Leibish Malbim (1809-1879) explained this passage as follows: Toward the end of the first Temple era, the people began increasingly to seek direction from false prophets, who prophesied in the name of idols. These prophets would demand top dollar for their services and, having received their payment, would mouth platitudes which did nothing to satiate the spiritual hunger within the people's hearts.

Hashem asks the people, "Why do you give of your money to hear these words, which in the end will leave you with nothing to show for the effort? Heed instead the words of my prophets, whose call you will find echoed within your own hearts. The ideas they express, and the G-dly service they ask of you, represent an achievement which you will truly experience with a sense of fulfillment."

Today we don't encounter any false prophets, of course. Yet all too often, we find ourselves expending our precious energies on the "false idols" which are found thin our own lifestyles. If we filled our lives instead with Torah and mitzvos, we would surely find the experience infinitely more enriching.