Hebrews 12:26

Whose voice then shook the earth
That is, at the giving of the law on Mount Sinai: Christ was then present; his voice was then heard; which was either the voice of thunder, or the voice of the trumpet, or rather the voice of words: this shook the earth, Sinai, and the land about it, and the people on it; which made them quake and tremble, even Moses himself; see ( Exodus 19:18 ) ( Psalms 68:8 )

but now he hath promised, saying
in ( Haggai 2:6 )

yet once more I shake not the earth only, but also heaven;
not only the land of Judea, and particularly Jerusalem, and the inhabitants of it, who were all shaken, and moved, and troubled at the news of the birth of the Messiah, the desire of all nations, the prophet Haggai speaks of, ( Matthew 2:2 Matthew 2:3 ) but the heaven also; by prodigies in it, as the appearance of a wonderful star, which guided the wise men from the east; and by the motions of the heavenly inhabitants, the angels, who descended in great numbers, and made the heavens resound with their songs of praise, on account of Christ's incarnation, ( Matthew 2:2 ) ( Luke 2:10 Luke 2:13 Luke 2:14 ) . How the apostle explains and applies this, may be seen in the next verse.