This seems so far beyond what we see. This is a common phrase to describe the totality of something. The uniqueness of God. His purposes are secure not only because He is the Sovereign Lord but also the gracious Savior. Thirst symbolized man's need of life-giving grace.
Water symbolizes the blessings and benefits of salvation.
God provided life-saving water for the people in the wilderness. The water baptisms which He ordained signified cleansing from sin and defilement. Because He is the Sovereign Lord. Because He is the gracious Savior. This word refers to a victory that is actively fought for and won.