For by me thy days shall be multiplied - Vice shortens human life, by a necessity of consequence: and by the same, righteousness lengthens it. There is a long addition here in the Septuagint, Syriac, and Vulgate: "He who trusts in falsity feeds on the winds; and is like him who chases the fowls of heaven. He forsakes the way of his own vineyard, and errs from the paths of his own inheritance. He enters also into lonely and desert places, and into a land abandoned to thirst; and his hands collect that which yieldeth no fruit."

For by me thy days shall be multiplied,.... These are the words of Wisdom, and contain a reason and argument why her call and advice in the preceding verses should be listened unto, since she gives long life to her followers. She is a tree of life unto them, the author and giver of spiritual and eternal life; by means of her bread and her wine spiritual life is maintained, promoted, and preserved; and length of days, for ever and ever, is the gift of her right hand; see Proverbs 3:16. The Targum is,
"for by it thy days shall be multiplied;''
which seems to refer it to the fear of the Lord, the beginning of wisdom, in Proverbs 9:10, to which long life is attributed; see Proverbs 10:27;
and the years of thy life shall be increased; or, "they shall add years of life to thee" (o); wisdom and understanding, the fear of the Lord, and the knowledge of the Holy; if not in this world, yet in the world to come, which will be without end.
(o) "et addent tibi annos vitae", Baynus, Cocceius.

(Compare Proverbs 3:16-18; Proverbs 4:10).

The singular reason for this proverb of Wisdom is now given:
"For by me will thy days become many,
And the years of thy life will be increased."
Incorrectly Hitzig: "and years of life will increase to thee;" הוסיף is always and everywhere (e.g., also Job 38:11) transitive. In the similar passage, Proverbs 3:2, יוסיפו had as its subject the doctrine of Wisdom; here חכמה and בינה it is not practicable to interpret as subj., since 11a Wisdom is the subject discoursing - the expression follows the scheme, dicunt eos = dicuntur, as e.g., Job 7:3; Gesen. 137 - a concealing of the operative cause, which lies near, where, as Proverbs 2:22, the discourse is of severe judgment, thus: they (viz., the heavenly Powers) will grant to thee years of life (חיּים in a pregnant sense, as Proverbs 3:2) in rich measure, so that constantly one span comes after another. But in what connection of consequence does this stand with the contents of the proverb, Proverbs 9:10? The ancients say that the clause with כי refers back to Proverbs 9:5. The Proverbs 9:7-10 (according also to Fl.) are, as it were, parenthetic. Hitzig rejects these verses as an interpolation, but the connection of Proverbs 9:11 with 5f. retains also something that is unsuitable: "steps forward on the way of knowledge, for by me shall thy days become many;" and if, as Hitzig supposes, Proverbs 9:12 is undoubtedly genuine, whose connection with Proverbs 9:11 is in no way obvious, then also will the difficulty of the connection of Proverbs 9:7-10 with the preceding and the succeeding be no decisive mark of the want of genuineness of this course of thought. We have seen how the progress of Proverbs 9:6 to 7 is mediated: the invitation of Wisdom goes forth to the receptive, with the exclusion of the irrecoverable. And Proverbs 9:11 is related to Proverbs 9:10, as the proof of the cause from the effect. It is the fear of God with which Wisdom begins, the knowledge of God in which above all it consists, for by it is fulfilled the promise of life which is given to the fear of God, Proverbs 10:27; Proverbs 14:27; Proverbs 19:23, cf. Deuteronomy 4:40, and to humility, which is bound up with it. Proverbs 10:17.