¹ sn The metaphor is meant to signify that the disciple will be closely related to and familiar with wisdom and understanding, as close as to a sibling. Wisdom will be personified in the next two chapters, and so referring to it as a sister in this chapter certainly prepares for that personification.

² sn The verse is a rhetorical question; it is affirming that no one can say this because no one is pure and free of sin.

³ tn The verb form זִכִּיתִי (zikkiti) is the Piel perfect of זָכָה (zakhah, “to be clear; to be clean; to be pure”). The verb has the idea of “be clear, justified, acquitted.” In this stem it is causative: “I have made my heart clean” (so NRSV) or “kept my heart pure” (so NIV). This would be claiming that all decisions and motives were faultless.

⁴ sn The Hebrew verb translated “I am pure” (טָהֵר, taher) is a Levitical term. To claim this purity would be to claim that moral and cultic perfection had been attained and therefore one was acceptable to God in the present condition. Of course, no one can claim this; even if one thought it true, it is impossible to know all that is in the heart as God knows it.