Hebrews 12:21

And so terrible was the sight, that Moses said, I exceedingly fear and quake:)

And so terrible was the sight,.... Of the smoke, fire, and lightnings; or of God himself, who descended on the mount; with which agrees the Arabic version, which renders the words, "and so terrible was he who vouchsafed himself to be seen"; not in the bush burning with fire; at which time Moses was afraid to look upon God, Exodus 3:6 but on Mount Sinai, when the law was given:

that Moses said, I exceedingly fear and quake: perhaps he might say this, when he spake, and God answered him, Exodus 19:19. These words are nowhere recorded in Scripture; wherefore the apostle had them either by divine revelation, or from tradition, confirmed by the former: for the Jews have a notion that Moses did quake and tremble, and when upon the mount; and that he expressed his fear and dread. They have such a tradition as this {e};

"when Moses ascended on high, the ministering angels said before the holy blessed God, Lord of the world, what has this man, born of a woman, to do among us? he said unto them, to receive the law he is come; they replied before him, that desirable treasure, which is treasured up with thee, nine hundred, and seventy, and four generations, before the world was created, dost thou seek to give to flesh and blood? "What is man, that thou art mindful of him, and the son of man, that thou visitest him? who hast set thy glory above the heavens!" The holy blessed God said to Moses, return them an answer; he said, before him, Lord of the world, ane aryytm, "I am afraid", lest they should burn, (or consume) me, with the breath of their mouth.''

Compare this last clause with 2 Thessalonians 2:8 and elsewhere {f} those words being cited, he called unto Moses, Exodus 25:16 it is observed:

"this Scripture comes not, but wyle Myyal "to terrify him"; that so the law might be given with fear, fervour, and trembling; as it is said, Psalms 2:11''

Once more {g},

"at the time that the holy blessed God said to Moses, "go, get thee down, for thy people have corrupted themselves",

Exodus 32:7 hvm ezedza, "Moses trembled"; and he could not speak, &c.''

And again, it is said {h}, that when Moses was on Mount Sinai, supplicating for the people of Israel, five destroying angels appeared, and immediately hvm aryytn, "Moses was afraid". Now this circumstance is mentioned by the apostle, to aggravate the terror of that dispensation; that Moses, a great and good man; and who had much familiarity with God; the general of the people of Israel; their leader and commander; a man of great courage and presence of mind; and was their mediator between God and them; and yet feared, and quaked: the best of men are not without sin; and the most holy man on earth cannot stand before a holy God, and his holy law, upon the foot of his own righteousness, without trembling: it is an awful thing to draw nigh to God; and there is no such thing as doing it without a Mediator; and that Mediator must be more than a creature: and it is our happiness that we have such a Mediator, who never feared, nor quaked; who failed not, nor was he discouraged.

{e} T. Bab. Sabbat, fol. 88. 2. Yalkut, 2. par. 2. fol. 92.
{f} T. Bab. Yoma, fol. 4. 2.
{g} Zohar in Exod. fol. 84. 4.
{h} Midrash Kohelet, fol. 69. 4.