Bible

1.  We have two versions of Ex 1:22.  The Masoretic Text (MT) reads:

Pharaoh commanded all his people, “Every boy that is born you shall throw into the Nile, but you shall let every girl live.”

The Samaritan Pentateuch (SP) reads:

Pharaoh commanded all his people, “Every boy that is born to the Hebrews you shall         throw into the Nile, but you shall let every girl live.”

What is the problem that gave rise to the variant tradition?  Also, which version is likely original and why?

2.  What are the MT and SP?

3.  In the notes to Ex 12:13, 23, the editor notes the appearance of a demonic figure called “the destroyer.”  On the basis of Ex 12, what is the relation between God and this figure?  Have we met anything like “the destroyer” before and, if so, where?