Amsal 3:21

3:21 My child, do not let them ¹  escape from your sight;

safeguard sound wisdom and discretion. ² 

Amsal 3:23

3:23 Then you will walk on your way ³  with security,

and you ⁴  will not stumble. ⁵ 

[3:21]  ¹ tn The object of the verb “escape” is either (1) wisdom, knowledge, and understanding in vv. 13-20 or (2) “wisdom and discretion” in the second colon of this verse. Several English versions transpose the terms “wisdom and discretion” from the second colon into the first colon for the sake of clarity and smoothness (e.g., RSV, NRSV, NIV, TEV, CEV).
NIV takes the subject from the second colon and reverses the clauses to clarify that.

[3:21]  ² tn Or: “purpose,” “power of devising.”

[3:23]  ³ tn The noun דַּרְכֶּךָ (darkekha, “your way”) functions as an adverbial accusative of location: “on your way.”

[3:23]  ⁴ tn Heb “your foot.” The term רַגְלְךָ (raglÿkha, “your foot”) functions as a synecdoche of part (= foot) for the whole person (= you).

[3:23]  ⁵ sn The verb נָגַף (ragaf, “to strike; to smite”) sometimes means “to stumble” against a stone (e.g., Ps 91:12). Here the object (“stone”) is implied (BDB 619 s.v.). This is a figure (hypocatastasis) comparing stumbling on a stone in the path to making serious mistakes in life that bring harm.