“But when they saw him walking upon the sea, they supposed it had been a spirit, and cried out:”
Mark 6:49 — Greek Interlinear
Church Fathers on Mark 6:49
But it is with reason that we wonder how Mark says, that after the miracle of the loaves the disciples crossed the sea of Bethsaida, when Luke relates that the miracle was done in the parts of Bethsaida [Luke 9:10], unless we understand that Luke means by the desert which is Bethsaida not the country immediately around the town, but the desert places belonging to it. But when Mark says that they should 'go before unto Bethsaida,' the town itself is meant.
But when He had dismissed the crowd, He goes up to pray, for prayer requires rest and silence.
But how could they understand this, except from His going a different way, wishing to pass them as strangers; for they were so far from recognizing Him, as to take Him for a spirit.