## will harden his heart ##

Possible meanings are 1) "will make him unwilling to obey you" or 2) "will make him unwilling to obey me."

## Israel is my son ##

The word "Israel" is a shortened form of "the people of Israel." (See: [[rc://en/ta/man/translate/figs-metonymy]])

## is my son, my firstborn ##

"is like my son, my firstborn" or "is like a firstborn son to me"  (See: [[rc://en/ta/man/translate/figs-metaphor]])

## you have refused to let him go ##

The word "him" refers to the people of Israel as God's son. (See: [[rc://en/ta/man/translate/figs-metonymy]])

## I will certainly kill your son, your firstborn ##

The word "son" here refers to the actual son of Pharaoh.