Charles Ellicott Commentary Psalms 33:7

"He gathereth the waters of the sea together as a heap: He layeth up the deeps in store-houses." — Psalms 33:7 (ASV)

As an heap. —The image explains itself (so we speak of waves “mountains high”) without reference to the passage of either the Red Sea or the Jordan. Still less is there a comparison to heaps of corn, as some think, since storehouses in the next clause are not necessarily barns, but reservoirs. But the Septuagint, Vulgate, and all ancient interpreters read nôd (“a skin”), instead of nêd (“a heap”), and make the reference to the rain, the clouds being considered as bottles. Compare this with Job 38:37.