And when the disciples saw him walking on the sea,.... It being now morning, and perhaps might have moon light; and besides, there is always more light upon the water than land; they were able to discern something like a man, walking upon the surface of the sea, but had not light enough to distinguish what, or who it was; and, moreover, had no thought of Christ, or expectation of seeing him; and the appearance of a man walking upon the waters being so unusual, and astonishing,they were troubled, saying it is a spirit: a nocturnal apparition, a demon in human form.
The Jews, especially the sect of the Pharisees, had a notion, from whom the disciples might have their's, of spirits, apparitions, and demons, being to be seen in the night; hence that rule ,"it is forbidden a man to salute his friend in the night, for we are careful, lest awh dv, "it should be a demon".'
'They say a great many things of one tylyl, "Lilith", that has its name from hlyl, "the night", a she demon, that used to appear in the night, with an human face, and carry off young children, and kill them.
Some such frightful notions had possessed the minds of the disciples:and they cried out for fear, as persons in the utmost consternation, in the greatest danger, and in want of help: the fear of spirits arises from the uncommonness of their appearance; from their superiority to men in power and strength; from the enmity there is between men and evil spirits; and from a general notion of their doing hurt and mischief: hence, demons are, by the Jews, calledNyqyzm, "hurtful", or "hurting", all their study being to do hurt to men; and the same word is here used in Munster's Hebrew Gospel: add to all this, that the fear of the disciples might be increased, through a vulgar notion among seafaring men, that such sights are ominous, and portend evil to sailors; and they might the more easily be induced to give credit to this, and fear, since they were already in such imminent danger.
T. Bab. Megilla, fol. 3. 1. Sanhedrim, fol. 44.