For their feet run to evil - The whole of this verse is wanting in the Septuagint, and in the Arabic.

For their feet run to evil,.... To the evil of sin, to commit robberies and murder, and all manner of iniquity; they are eager upon it, and in haste and swift to do it, Proverbs 6:18 (x); being carried away with their inordinate affections, which are as feet to the soul; and drawn aside with their lusts, and pushed on by Satan, and, encouraged by one another, and so rush on headlong to the evil of punishment also; and which is a reason why their ways and paths should be abstained from, because they bring upon them swift destruction; it is to their own hurt they run, as Jarchi interprets it; though the first sense seems best to agree with what follows;
and make haste to shed blood; the blood of innocent persons, in order to get their substance, to cover their iniquity and shame, and that no information may be given of them; this is mentioned as having something very horrible in it, in order to deter from joining with them.
(x) "Velox ad facinus", Claudian. in Rufin. l. 1. v. 240.

The first argument to enforce the warning:
For their feet run to the evil,
And hasten to shed blood.
That this is their object they make no secret (Proverbs 1:11.); but why is it that such an object as this should furnish no ground of warning against them, especially as on this beginning the stamp of that which is morally blamable is here impressed with לרע? Besides, this circular movement of the thoughts is quite after the manner of this poet; and that Proverbs 1:16 is his style, Proverbs 6:18 shows. The want of this distich (Proverbs 1:16 = Romans 3:15) in lxx B. א. weighs heavier certainly than the presence of it in lxx A. (Procop., Syro-Hezap.), since the translation is not independent, but is transferred from Isaiah 59:7; but if for the first time, at a later period, it is supplied in the lxx, yet it has the appearance of an addition made to the Hebr. text from Isaiah 59:7 (Hitzig, Lagarde); cf. Comm. on Isaiah, 40-66. לשׁפּך is always pointed thus; for, as a regular rule, after ל as well as מ sa llew s the aspiration disappears; but in Ezekiel 17:17 בּשׁפּך is also found, and in this case (cf. at Psalm 40:15) the punctuation is thus inconsequent.