6:19 thirty furlongs. He was “in the midst of the sea” (Mark 6:47). Also see note on Luke 24:13.

6:19 walking on the sea. This fifth miracle of creation described in John’s gospel was also a fulfillment of the Messianic prophecy of Isaiah 43:2. “When thou passest through the waters, I will be with thee; and through the rivers, they shall not overflow thee.” In this instance, Christ evidently created an anti-gravitational force of some kind, enabling Him to set aside the most basic of all scientific laws. The law of conservation of energy stipulates that energy (that is, the capacity to accomplish work, moving forces through distances) be neither created nor annihilated. Jesus, as the Creator, alone can supersede or extend this law.