John Calvin Commentary Psalms 69:2

"I sink in deep mire, where there is no standing: I am come into deep waters, where the floods overflow me." — Psalms 69:2 (ASV)

I am sunk in deep mire, where there is no standing place. Here he compares his afflictions to a deep sink of mire, where there is still greater danger. For if a man fixes his feet on a solid bottom, he may raise himself up; indeed, there have been many instances where people, placing their feet on the bottom, have by a sudden spring emerged and escaped the peril of the waters. But when a man finds himself once sunk in some slough or muddy river, it is all over with him; he has no means of saving himself.

The Psalmist cites additional circumstances to illustrate his afflicted condition. He declares that he was inundated by the flowing of the waters; an expression indicating the disorder and confusion that his distresses and persecutions produced.