All Your breakers and Your waves have gone over me.
All Thy waves (v. 7) can also be taken in a good sense, namely, that the high waves, that is, the swirling waters of the deep and the flow of living waters, of which [the psalmist] had already spoken, that is, the Gospels, passed over the church and made it glad, as also Psalm 93:4 says: "With the noise of many waters wonderful are the surges of the sea." Hence an old translation reads, "all thy vaulted works," which properly expresses the peculiarity of evangelical teaching; for it does not rest on the earth or on human wisdom, but it arches overhead and takes every understanding captive to the obedience of Christ (2 Corinthians 10:5) . . . . Those are the salutary floods and surges of the Lord, which submerge the flesh and its desires and cause the soul or spirit to swim and carry it suspended.
From First Lectures on the Psalms, on Psalm 42 (Luther's Works 10:201-2)