The Mighty One, God, the Lord, has spoken, And summoned the earth from the rising of the sun to its setting.” (Psalm 50:1, NASB95)

Asaph uses three names of the Lord to start off his psalm here:  El, Elohim, and Yahweh, which we can translate: “The God, God, and Lord.” The LEB translates here: “The Supreme God, God, Yahweh.”  The point is that God is the supreme King and above him there is no one and nothing else.

When the King speaks, his subjects obey, and this is never more true than when the King speaks to his creation.  Here he summons or calls for the earth “from the rising of the sun to its setting.” The King is in control of his creation, both animate and inanimate, and when the King speaks his creation obeys, to the praise of His glory.

In all of creation, the only creation of God that [sometimes] does not obey, is Man himself.  This is the tragedy of being a free moral creature, the triumph came at the cross where the King himself paid for our sins, and gave us the ability to respond when summoned like the earth has done all along.