Compare Luke 2:52. These are the two conditions of true human growth.

So shalt thou find favor - Thou shalt be acceptable to God, and thou shalt enjoy a sense of his approbation.
And good understanding - Men shall weigh thy character and conduct; and by this appreciate thy motives, and give thee credit for sincerity and uprightness. Though religion is frequently persecuted, and religious people suffer at first where they are not fully known; yet a truly religious and benevolent character will in general be prized wherever it is well known. The envy of men is a proof of the excellence of that which they envy.

So shall thou find favour,.... Or "grace" (i); the grace of God, and larger measures of it; as Noah did, Genesis 6:8; which are communicated to men when in the way of their duty: or good will, esteem, and respect, among men; as Joseph had with Potiphar, and the keeper of the prison, Genesis 39:4;
and good understanding in the sight of God and man; as Christ, as man, had in the sight of both, Luke 2:52; that is, to be taken notice of, regarded, and approved by both. Some render it "good success" (k); prosperity in things temporal and spiritual; see Psalm 111:10. There is something lovely, and of good report, in a close attention to the doctrines and duties of religion; which make a man amiable in the sight of others, and which is followed with a blessing from the Lord.
(i) "gratiam", Pagninus, Montanus, Tigurine version, &c. (k) "successum optimum", Junius & Tremellius.

favour--grace, amiability (Proverbs 22:11; Psalm 45:2); united with this,
a good understanding--(Compare Margin), a discrimination, which secures success.
in the sight . . . man--such as God and man approve.

To the admonitory imper. there follows here a second, as Proverbs 4:4; Proverbs 20:13; Amos 5:4; 2-Chronicles 20:20, instead of which also the perf. consec. might stand; the counsellor wishes, with the good to which he advises, at the same time to present its good results. שׂכל is (1-Samuel 25:3) the appearance, for the Arab. shakl means forma, as uniting or binding the lineaments or contours into one figure, σχῆμα, according to which שׂכל טוב may be interpreted of the pleasing and advantageous impression which the well-built external appearance of a man makes, as an image of that which his internal excellence produces; thus, favourable view, friendly judgment, good reputation (Ewald, Hitzig, Zckler). But everywhere else (Proverbs 13:15; Psalm 111:10; 2-Chronicles 30:22) this phrase means good, i.e., fine, well-becoming insight, or prudence; and שׂכל has in the language of the Mishle no other meaning than intellectus, which proceeds from the inwardly forming activity of the mind. He obtains favour in the eyes of God and man, to whom favour on both sides is shown; he obtains refined prudence, to whom it is on both sides adjudicated. It is unnecessary, with Ewald and Hitzig, to assign the two objects to God and men. In the eyes of both at the same time, he who carries love and faithfulness in his heart appears as one to whom חן and שׂכל טוב must be adjudicated.

Understanding - Whereby to know thy duty, and to discern between good and evil. Of God - Grace or favour with God, and that understanding which is good in God's sight.