In this verse the father depicts the benefits and advantages which shall follow from "receiving his words" (Proverbs 4:10), i.e. from attending to his counsels and imbibing the principles of wisdom. The whole course of life shall be freed from obstacles or impediments, from anxiety, perplexity, or difficulty, or from vacillation.
When thou goest may refer to the daily walk, to the common and ordinary events or circumstances incidental to life, just as the corresponding when thou runnest may refer to cases of emergency when promptness and decisive action are called for.
In both cases Wisdom, by inspiring unity of principle, gives freedom of movement; in ordinary cases it removes embarrassment and perplexity arising from conflicting interests drawing now in one direction, now in another, and in extraordinary cases it supplies a rule of conduct which prevents our falling into mistakes and errors.
Or the verse may refer to the prosperity which shall attend all the undertakings of those who are in Wisdom's ways, whether they advance slowly or rush forward with the impetuosity of youth, whether they act with deliberation or with haste.
Shall not be straitened (lo-yetsar); i.e. shall not be narrowed or confined; Vulgate, non arctabuntur; LXX; οὑ συγκλεισθήσεται, The future yetsar only occurs four times in the Scriptures—here, and Job 18:7; Job 20:22; Isaiah 49:19.
It is usually derived from the root yatsar, which, however, is not found, cognate with tsur, "to straiten," "to be narrow." Yetsar, however, always occurs in the passive sense, though an active signification is given it by the Rabbi Nathan ben Jechiel, quoted by Delitzsch, in loc; who renders, "Thou shall not need to bind together, or hedge up thy way."
The roots yatsar and tsur partake more or less of the idea of binding up, oppressing, putting into narrow and confined circumstances and limits. By the expression that "the steps are straitened" we may understand, therefore, that there is a want of freedom for their movements, and consequently that they are impeded or cramped.
The Arabic expression. "to contract the feet," signifies the diminishing of good fortune. Compare the similar expression in Job 18:7, "The steps of his strength shall be straitened." The psalmist presents the idea of the verse under a different form, "Thou hast enlarged my steps under me, so that my feet did not slip" (Psalms 17:1-15 :36).
Thou shalt not stumble; lo-thik-kashel, hiph. future. The niph. nikshal, equivalent to the kal kadshal, signifies properly "to totter," "to sink down," used of one about to fall. The primary idea, however, usually disregarded, of kashal, is "to totter in the ankles," equivalent to the Latin talipedare.
It occurs again in Proverbs 4:16, and is a different verb from "stumble" in Proverbs 3:23 (which see).