Exodus 5:2

Exo 5:2 And Pharaoh said, Who [is] the LORD, that I should obey his voice to let Israel go? I know not the LORD, neither will I let Israel go.

Ver. 2. Who is the Lord? ] God’s attributes either show what he is, or who he is. To the question of Moses - What he is? - God gave a short answer, "I am." To this second by Pharaoh, Who he is? - God made a large reply, till Pharaoh was compelled to answer himself, "The Lord is righteous."