But who can detect one’s own errors?
Clear me from hidden faults.
The CSB renders it this way:
Who perceives his unintentional sins?
Cleanse me from my hidden faults.
In the background of this passage is the Levitical concern about "unintentional sins" described in Leviticus 4 and 5. There are ways in which we go against God's will without even knowing it.
What interrupted me about these concerns over "unintentional sins" and "hidden faults" was the question of my own self-assessment. Just how blind am I to my sins and faults? And what is the source of that blindness?
While I can be critical of Sigmund Freud, one of this great contributions, in my estimation, was his description of how we are masters at self-deception. We hide from ourselves. Much of this is due to defense mechanisms, ways we obscure or twist the truth to avoid a clear confrontation with ourselves.
And if this is true, just how large is that blind spot of mine? And how to bring more of it into view?
To be sure, this sort of soul work isn't what everyone needs at a given moment. People struggling with depression shouldn't be seeking out self-criticism. But moral hygiene requires some effort in taking honest reckonings of oneself. This brings to mind an image from Amos 7, a vision of a moral plumb line:
He showed me this: The Lord was standing there by a vertical wall with a plumb line in his hand. The Lord asked me, “What do you see, Amos?”
I replied, “A plumb line.”
Then the Lord said, “I am setting a plumb line among my people Israel..."
A plumb line, as I expect you know, is a weight attached to a line. You drop a plumb line from the top of or alongside a wall to see how far the wall is from vertical. Amos uses the image of a plumb line to describe the Lord's moral assessment of Israel. The plumb line is dropped among the people to reveal how "off" Israel is from vertical alignment.
In a similar way, if we want to bring our hidden faults into view, we can drop a plumb line in our lives. We can engage with the Ignatian practice called the examen of conscience. We can seek the input of those closest to us, opening ourselves to their feedback. We can embrace confessional and humble postures and practices.
Still, things will be missed. We'll never be wholly transparent to ourselves. As Psalm 19 says, "Who can detect one's own errors?" And so we continuously pray: "Lord, cleanse me of my hidden faults."

