Mark 6:49

“But when they saw him walking on the sea, etc..] (See Gill on “<401426>Matthew 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 “<401426>Matthew 14:26”).”

“See this passage explained in the notes at Matthew 14:22-36. Mark 6:52 They considered not the miracle of the loaves - They did not remember or call to mind the “power” which Jesus had shown in feeding the five thousand by a miracle, and that, having done that, he had power also to save them from the storm. Their heart was hardened - Their “mind” was dull to perceive it. This does not mean that they were “opposed” to Jesus, or that they had what we denominate “hardness of heart,” but simply that they were slow to perceive his power. They did not quickly learn, as they ought to have done, that he had all power, and could therefore allay the storm. The word “heart” is frequently used in this…”

“6:49-50 The disciples’ terror is understandable—humans cannot walk on water, so they concluded that they were seeing a ghost. As in many divine manifestations, the Lord gave a word of assurance: Don’t be afraid and Take courage! The reason is, I am here! It was not a ghost but Jesus—their friend, Savior, and Lord. • I am here!: Because Jesus’ walking on the sea and stilling the storm were miraculous, Mark’s original readers would have understood the exclamation I am as a parallel to God’s self-description in the Old Testament (Exod 3:14; Deut 32:39; Isa 41:4; 43:10-13) and thus as a reference to Jesus’ divinity.”

“they saw: Job 9:8 supposed: Job 4:14-16; Mat 14:25, Mat 14:26; Luk 24:37 Mark 6:50”