John Goldingay on Psalm 142:
How does prayer work? That is, how do you win Yhwh’s response to your need? The psalm’s four sections suggest four answers. First, talk about the way you are going to pray, maybe to other people, remembering that Yhwh can overhear what you are saying. Yhwh’s overhearing is not a threat but a blessing; when we overhear something not addressed to us, it can affect us more than hearing something that was addressed to us. Second, talk directly to Yhwh about how things are, about the nature of your need, and about what Yhwh knows. Even if Yhwh knows, talking about these things brings them to Yhwh’s attention, opens up the possibility of pushing them to the top of Yhwh’s agenda, and means that relationships between us and Yhwh are true and open. Third, ask for Yhwh’s full attention on the basis of Yhwh’s being the only person who can help. Fourth, urge Yhwh to help, and point out how this will bring Yhwh glory. These convictions that the psalm assumes are not ones Christians often assume about prayer.
John Goldingay, Baker Commentary on the Old Testament: Psalms 90–150, ed. Tremper Longman III, vol. 3 (Grand Rapids, MI: Baker Academic, 2006), 669.