Albert Barnes Commentary Psalms 119:113

"I hate them that are of a double mind; But thy law do I love." — Psalms 119:113 (ASV)

I hate vain thoughts - This begins a new portion of the psalm, distinguished by the Hebrew letter Samech (ס s), corresponding to our "s." The word translated "vain thoughts" occurs only in this place. It is translated by the Septuagint as παρανόμους (paranomous), meaning transgressors. The Latin Vulgate translates it similarly. Luther translates it as "die Flattergeister," meaning the frivolous-minded. The word means divided. It describes a person of a divided mind, one who has no sure faith regarding divine things but is driven here and there—a skeptic, a doubter. Compare James 1:8.

Thus, it refers not primarily to his own thoughts as being "vain" or worthless, but to a general state of mind or heart characterized by a lack of firmness, stability, or settled views—a state of mind that is wavering, doubtful, and skeptical regarding religion.

What is implied here regarding what he loved—by stating, in contrast, what he "hated"—is a mind settled in its convictions of truth and firm in its adherence to it. This describes a mind steadfast in religion, not vacillating, skeptical, or uncertain on the subject. This indicates that the psalmist sought such a state of mind for himself and valued it in others.

But your law do I love - I have no "divided" or unsettled feelings regarding that. I am conscious of a firm attachment to it. This thought he has repeatedly expressed in the psalm.