Albert Barnes Commentary Jonah 2:5

"The waters compassed me about, even to the soul; The deep was round about me; The weeds were wrapped about my head." — Jonah 2:5 (ASV)

The waters compassed me about, even to the soul - Words which to others were figures of distress (Psalms 69:2; see the introduction to Jonah), the waters have come even to the soul, were to Jonah realities.

Sunk in the deep seas, the water strove to penetrate at every opening. To draw breath, which sustains life, would have been death to him. There was but a breath between him and death.

The deep encompassed me, encircling him, meeting him wherever he turned, and holding him imprisoned on every side, so that there was no escape. And even if escape had otherwise been possible, he was bound motionless. The weed was wrapped around my head, like a grave-band.

"The weed" was the well-known seaweed. Even near the surface of the sea where a person can struggle, it twines around him, a peril even to the strong swimmer, often entangling him more, the more he struggles to extricate himself from it. But to one below, powerless to struggle, it was like his winding sheet.