Lest thou shouldest ponder the path of life, her ways are moveable, that thou canst not know them.
Lest thou shouldest ponder the path of life, her ways are moveable, (that) thou canst not know (them).
"Lest" expresses this-Her aim and tendency are toward death (Proverbs 5:6), so that thou canst not ponder the path of life (as I advised thee to do, Proverbs 4:26): do not, therefore, flatter thyself thou canst escape being dragged down with her "to death," if thou dost keep company with her. 'Her ways are so moveable' - i:e., so versatile, varied (Proverbs 30:18-19), and lubricous, and baffling all thy power of 'knowing them' (cf. Psalms 35:8, "at unawares;" Hebrew, 'which he knoweth not of'), that thou canst not escape destruction with her, unless thou standest quite aloof from her. Thou canst not touch pitch without being soiled by it.