Mark 6:47

And when even was come
The second evening, and it was properly night:

the ship was in the midst of the sea;
of Galilee, about twenty five or thirty furlongs from the shore; see ( John 6:19 ) ;

and he alone on the land;
upon the mountain. This is observed, partly to show what distress the disciples were in, in the midst of the sea, having a hard gale of wind, and their master not with them; and partly to show that there was no way, humanly speaking, of Christ's getting to the ship, in order to go over; and is an illustration of the following miracle, of walking so many furlongs, as he must, upon the water, in a stormy, blustering night, to get to it.