Albert Barnes Commentary Jonah 2:3

"For thou didst cast me into the depth, in the heart of the seas, And the flood was round about me; All thy waves and thy billows passed over me." — Jonah 2:3 (ASV)

For You had (or “did”) cast me into the deep - Jonah continues to describe the extremity of peril, from which God had already delivered him.

Sweet is the memory of perils past, for they speak of God’s Fatherly care. It is sweet to the prophet to tell God of His mercies; but this is sweet only to the holy, for God’s mercy convicts the careless of ingratitude.

Jonah then tells God how He had cast him vehemently forth into the “eddying depth,” where, when Pharaoh’s army sank like a stone (Exodus 15:5 and Exodus 15:10), they never rose, and that he was in the heart or center of the seas, from where no strong swimmer could escape to shore. The floods or flood (literally “river”), the sea with its currents, surrounded him, encompassing him on all sides; and, above, tossed its multitudinous waves, passing over him like an army trampling one prostrate underfoot.

Jonah remembered well the temple psalms and, using their words, united himself with those other worshipers who sang them, and taught us how to speak them to God.

The sons of Korah (Psalms 42:7) had poured out to God in these self-same words the sorrows which oppressed them. The rolling billows and the breakers, which, as they burst upon the rocks, shiver the vessel and crush man, are, he says to God, Yours, fulfilling Your will on me.