A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown [1882] at sacred-texts.com
Psalms Chapter 130
The penitent sinner's hope is in God's mercy only. (Psa 130:1-8)
depths--for great distress (Psa 40:2; Psa 69:3).
shouldest mark--or, "take strict account" (Job 10:14; Job 14:16), implying a confession of the existence of sin.
who shall stand-- (Psa 1:6). Standing is opposed to the guilty sinking down in fear and self-condemnation (Mal 3:2; Rev 6:15-16). The question implies a negative, which is thus more strongly stated.
Pardon produces filial fear and love. Judgment without the hope of pardon creates fear and dislike. The sense of forgiveness, so far from producing licentiousness, produces holiness (Jer 33:9; Eze 16:62-63; Pe1 2:16). "There is forgiveness with thee, not that thou mayest be presumed upon, but feared."
wait for the Lord--in expectation (Psa 27:14).
watch for, &c.--in earnestness and anxiety.
Let Israel, &c.--that is, All are invited to seek and share divine forgiveness.
from all his iniquities--or, "punishments of them" (Psa 40:12, &c.).