That thou mayest know. — Comp. Exodus 7:5; Exodus 7:17. Moses is not content that Pharaoh should simply acknowledge Jehovah as he had done (Exodus 8:8), but wishes him to be convinced that no other god can compare with Him.
Related Commentaries of Exodus 8:10
Exodus 8:10
10 And he said, To morrow.c And he said, Be it according to thy word: that thou mayest know that there is none like unto the LORD our God.