20 For they could not bear that which was commanded: "And if so much as a beast touches the mountain, it shall be stoned."
Hebrews 12:20 Cross References - CAB
Exodus 19:12-13
12 And you shall separate the people round about, saying, Take heed to yourselves that you go not up into the mountain, nor touch any part of it: whoever touches the mountain shall surely die.
13 A hand shall not touch it, for everyone that touches shall be stoned with stones or shot through with a dart, whether beast or man, it shall not live; when the voices and trumpets and cloud depart from off the mountain, they shall come up on the mountain.
Exodus 19:16
16 And it came to pass on the third day, as the morning drew nigh, there were voices and lightnings and a dark cloud on Mount Sinai. The voice of the trumpet sounded loud, and all the people in the camp trembled.
Deuteronomy 33:2
2 And he said, The Lord has come from Sinai, and has appeared from Seir to us, and has shone forth from Mount Paran, with the ten thousands of Kadesh; on His right hand were His angels with Him.
Romans 3:19-20
Galatians 2:19
19 For I through the law died to the law, that I might live to God.
Galatians 3:10
10 For as many as are of the works of the law are under the curse; for it is written, "Cursed is everyone who does not continue in all the things which are written in the book of the law, to do them."