But they were terrified and affrighted,.... At the sight of him, and at his sudden appearance among them, without being heard, or seen before, and the doors shut and bolted; they could not tell how to account for it, that it should be Jesus himself risen from the dead in his own body, though they had been just speaking of his resurrection, and had had a confirmation of it from the disciples that went to Emmaus: and supposed that they had seen a spirit; that what they saw was a phantom, or apparition, or a spirit, that had assumed, and appeared in, the shape of Jesus, and was not he himself.