He could see that the disciples were straining to row, because the wind was against them. About the fourth watch of the night, Jesus went out to them, walking on the sea. He intended to pass by them,
This passage of story we had Mat 14:22, etc., only what was there related concerning Peter, is omitted here. Here we have, I. The dispersing of the assembly; Christ constrained his disciples to go before by ship to Bethsaida, intending to follow them, as they supposed, by land. The people were loth to scatter, so that it cost him some time and pains to send them away.
Commenting on Mark 6:45-56
But when they saw him walking on the sea,.... See Gill on Mat 14:26; they supposed it had been a spirit; a phantom, a spectre, an apparition, a nocturnal demon: and cried out; as men affrighted at the sight, and fearing they should be hurt by it, or that it portended some evil to them; See Gill on Mat 14:26.
Verse 48. (z) "toiling in rowing" (a) "have passed"