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 31:15

31:15 Six days ³  work may be done, ⁴  but on the seventh day is a Sabbath of complete rest, ⁵  holy to the Lord; anyone who does work on the Sabbath day must surely be put to death.

[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.

[31:15]  ³ tn This is an adverbial accusative of time, indicating that work may be done for six days out of the week.

[31:15]  ⁴ tn The form is a Niphal imperfect; it has the nuance of permission in this sentence, for the sentence is simply saying that the six days are work days – that is when work may be done.

[31:15]  ⁵ tn The expression is שַׁבַּת שַׁבָּתוֹן (shabbat shabbaton), “a Sabbath of entire rest,” or better, “a sabbath of complete desisting” (U. Cassuto, Exodus, 404). The second noun, the modifying genitive, is an abstract noun. The repetition provides the superlative idea that complete rest is the order of the day.