1)
What is the purpose of "Et Barzel v'Oferes"?
1.
Rashi: First [the words] are carved into the rock, and afterwards they put lead over them to give a black appearance to the letters, to make them more recognizable. People who engrave in rock normally do so 1 .
1
Rashi: You cannot say that they used a lead stylus to engrave in rock. Lead is softer than rock!
2)
Why should they be engraved in rock?
1.
Ibn Ezra: They would not be erased.
2.
Malbim: They would remain until Dor Acharon.
