Hebrews 12:20

They could not bear the order: If even a beast touches the mountain, it will be stoned.

Exodus 19:12-13

Warn the people that they are forbidden to touch any part of the mountain. Anyone who touches the mountain will be put to death,

Exodus 19:16

On the morning of the third day there were thunder and lightning flashes and a thick cloud upon the mountain. A very loud trumpet sounded. It caused all the people in the camp to tremble.

Deuteronomy 33:2

Jehovah came from Mount Sinai. He rose like the sun over Edom and shone on his people from Mount Paran. Ten thousand angels were with him. A flaming fire was at his right hand.

Romans 3:19-20

We know that whatever the law says, it speaks to those under the law. Every mouth may be stopped and the entire world may become liable to God for punishment.

Galatians 2:19

I, through the law, died to the law that I might live to (for) God.

Galatians 3:10

Those who are of the works of the Law are under a curse. For it is written, Cursed is everyone who does not abide by all things written in the book of the Law, by obeying them.

Treasury of Scripture Knowledge

Summary

(For they could not endure that which was commanded, And if so much as a beast touch the mountain, it shall be stoned, or thrust through with a dart:

If so much

General references

Bible References

For they

Deuteronomy 33:2
Jehovah came from Mount Sinai. He rose like the sun over Edom and shone on his people from Mount Paran. Ten thousand angels were with him. A flaming fire was at his right hand.
Romans 3:19
We know that whatever the law says, it speaks to those under the law. Every mouth may be stopped and the entire world may become liable to God for punishment.
Galatians 2:19
I, through the law, died to the law that I might live to (for) God.
Galatians 3:10
Those who are of the works of the Law are under a curse. For it is written, Cursed is everyone who does not abide by all things written in the book of the Law, by obeying them.

If so much

Exodus 19:13
with stones or arrows, and no one must touch the body of a person killed in this way. Even an animal that touches this mountain must be put to death. You may go up the mountain only after a signal is given on the trumpet.

General references

Exodus 34:3
No man may come with you or even be seen anywhere on the mountain. Even the flocks and herds may not graze in front of this mountain.
Deuteronomy 5:23
Fire blazed from the mountain, and you heard the voice coming from the darkness. Then your elders came to me.