This psalm has four parts which explain the logic of the psalm
94:1 Heading: Yhwh is the avenging God
A 94:2-7 Problem: The wicked are unrestrained
B 94:8-19 Answer: Yhwh takes notice and will act
A' 94:20-23 Result: The wicked will be repaid
The wicked which encircle the suppliant also encircle the structure of the psalm. There are a few different words, such as רשׁע (rasha`, wicked 4x: 94:3,3,13,21); רע/רעה/רעע (ra', evil, 3x: 94:13 (evil days), 16 (evildoers), 23 (evil)); און (awon, iniquity 3x 94:4,16,23). They are clustered in 3-4, 13-16, 21-23), at the beginning and the end to explain the problem and hoped-for result, and in the centre to explain the context against which they call out to God for rescue.
The description of God in this psalm is twofold. Firstly with reference to God's power and protection, Yhwh is an avenging God, he is the judge of the earth, he is a helper, the one who sustains, a stronghold and a rock of refuge (1-2, 17-18, 22)
Secondly, God is the teacher, the instructor, the one who sees and the one who knows (8-12). And this is where this psalm stands out. They scoff in v7, "Yah will not see us; the God of Jacob will not take notice." The response in v8-11 is an expansive retort, using the same verb בין (bin), "Take notice! ... Wise up! Does the one who made ears not hear, the one who formed the eye, does he not take notice?"
Because he is the creator of the ears and eyes, to scoff "he will not notice" is to demonstrate a dangerous ignorance regarding the information gathering abilities and activities of Yhwh. The psalmist plays on the fluidity of the verb יסר (yasar, to instruct/warn/rebuke) to explain that the one who instructs nations with knowledge also reproves them (10), but he also gives this to individuals, to the one who is thereby blessed (12).
This all explains the way Yhwh cares for his people in the following verses, and in particular, in the context of evil. It is not a military victory that is explicitly promised, but a true knowledge of God and of the cosmos, which gives a calm, which soothes one's soul (v19).
Is this an Exodus psalm?
I've been arguing that 90-106 (Book IV) is an Exodus collection. How then does this psalm work in that context? It does seem as if there is something of a flow, working through the Exodus story bit by bit, but here, it appears to jump forward to the giving of the law from 20-23, but especially the importance of the law in the context of evil as is described in Exodus 23:2, "Don't follow after the many in doing evil". Rather, be instructed by Yhwh to stand firm in his teaching (תורה, torah), v12 - this word providing the other link back.
In this way, perhaps Psalm 94 is a hidden wisdom psalm rather than a psalm for rescue. For although the default desire is for divine intervention, in this psalm it is the instruction of Yhwh, which, even if not rescuing, enables one to stand firm despite the evil which encircles, which, if nothing else, is surely one of the key messages from the entire Exodus experience.
