Discretion shall preserve thee - מזמה mezimmah. See on Proverbs 1:4 (note). Here the word is taken in a good sense, a good device. The man invents purposes of good; and all his schemes, plans, and devices, have for their object God's glory and the good of man: he deviseth liberal things, and by liberal things he shall stand. Coverdale translates, "Then shall Counsel preserve thee." A very good translation, much better than the present.

(f) Discretion shall preserve thee, understanding shall keep thee:
(f) The word of God will guide you, and teach you how to govern yourself.

Discretion shall preserve thee,.... Which wisdom or the Gospel gives, or the Lord by the means of it; for the Gospel makes a man wise and discreet in the business of salvation, and in his conduct and deportment; and the discretion it gives him will put him upon his guard, and direct him to watch against every error, and every false way. And so the words may be rendered, "discretion will watch over thee"; to keep thee from everything pernicious in doctrine and practice. The Septuagint version renders it, "good counsel"; which wisdom gives, and the Gospel is full of; and which, if attended to, is a means of the preservation of the saints;
understanding shall keep thee; which is only the same thing expressed in other words. The Septuagint version renders it, "an holy thought"; and the Arabic version, "a just thought shall preserve thee in thy last times". What these are a means of keeping and preserving from is explained in the following verses.