Exodus 19:12

19:12 You must set boundaries ¹  for the people all around, saying, ‘Take heed ²  to yourselves not to go up on the mountain nor touch its edge. Whoever touches the mountain will surely be put to death!

Exodus 19:21

19:21 The Lord said to Moses, “Go down and solemnly warn ³  the people, lest they force their way through to the Lord to look, and many of them perish. ⁴ 

[19:12]  ¹ tn The verb is a Hiphil perfect (“make borders”) with vav (ו) consecutive, following the sequence of instructions.

[19:12]  ² tn The Niphal imperative (“guard yourselves, take heed to yourselves”) is followed by two infinitives construct that provide the description of what is to be avoided – going up or touching the mountain.

[19:21]  ³ tn The imperative הָעֵד (ha’ed) means “charge” them – put them under oath, or solemnly warn them. God wished to ensure that the people would not force their way past the barriers that had been set out.

[19:21]  ⁴ tn Heb “and fall”; NAB “be struck down.”