Wherewithal shall a young man cleanse his way? by taking heed thereto according to thy word.
Wherewithal shall a young man cleanse his way? The lusts of young men are naturally strong, and prone to bring defilement on the soul (cf. Proverbs 1:4; Proverbs 20:11).
By taking heed (thereto) according to thy word. "Thereto" - namely, to "his way" (cf. Psalms 17:4).