"who has control over the stars" or "who blocks the stars from view"
## who by himself stretches out the heavens ##
This is a figurative description of how the skies range from one horizon to the other. "who alone stretches out the heavens"
## who tramples down and subdues the waves of the sea ##
This is a reference to the creation story in which God controls the chaotic sea. "who marches on the waves of the sea" or "who calms the waves of the sea"
## who makes the Bear, Orion, and the Pleiades ##
These refer to constellations, groups of stars picturing individuals and objects.
## Orion ##
a group of stars picturing a famous hunter in Greek mythology