能不害怕吗？犹太人害怕见到神的面，因为知道自己不够圣洁，旧约中说一般情况下无人能见神的面。

Barnes 的注解：
Mat 17:6 -
They fell on their face - They entered into the cloud, or the cloud enveloped them, Luk_9:34. “They were therefore afraid.” They were awed at the presence of God, and prostrated themselves in solemn adoration on the ground, and their fears were removed only by the voice of their beloved Master. No man can see God and live; and it is only the glory of God, as it shines in the face of Christ (see 2Co_4:6), that mortals can bear.


Mat 17:1 过了六天，耶稣带著彼得、雅各，和雅各的兄弟约翰，暗暗的上了高山，
Mat 17:2 就在他们面前变了形像，脸面明亮如日头，衣裳洁白如光。
Mat 17:3 忽然，有摩西、以利亚向他们显现，同耶稣说话。
Mat 17:4 彼得对耶稣说：「主啊，我们在这里真好！你若愿意，我就在这里搭三座棚，一座为你，一座为摩西，一座为以利亚。」
Mat 17:5 说话之间，忽然有一朵光明的云彩遮盖他们，且有声音从云彩里出来，说：「这是我的爱子，我所喜悦的。你们要听他！」
Mat 17:6 门徒听见，就俯伏在地，极其害怕。
Mat 17:7 耶稣进前来，摸他们，说：「起来，不要害怕！」
Mat 17:8 他们举目不见一人，只见耶稣在那里。