Jamieson, Fausset and Brown on Mark 4:39

39. And he arose, and rebuked the wind--"and the raging of the water" (Lu 8:24).

and said unto the sea, Peace, be still--two sublime words of command, from a Master to His servants, the elements.

And the wind ceased, and there was a great calm--The sudden hushing of the wind would not at once have calmed the sea, whose commotion would have settled only after a considerable time. But the word of command was given to both elements at once.