Turn ye not unto idols. The word used for idols, elilim, meaning nothings, is contrasted with Elohim, God. Psalms 115:1-18 exhibits this contrast in several of its particulars. Cf. St. Paul's statement, "We know that an idol is nothing in the world, and that there is none other God but one" (1 Corinthians 8:4).
"If the heart of man becomes benumbed to the use of images of false gods of any kind, he sinks down to the idols which are his ideals, and becomes as dumb and unspiritual as they are" (Lunge). The remainder of the verse forbids the transgression of the second commandment, as the earlier part of the verse forbids the transgression of the first commandment: nor make to yourselves molten gods, as was done by Jeroboam when he set up the calves (1 Kings 12:23).