Exodus 9:1

Then the Lord said unto Moses
The same day the plague of the flies was removed: go in unto Pharaoh
boldly, without any fear of him or his court: and tell him, thus saith the Lord God of the Hebrews:
speak in the name of Jehovah, the God whom the Hebrews worship, and who owns them for his people, and has a special love for them, and takes a special care of them, and is not ashamed to be called their God, as poor and as oppressed as they be: let my people go,
that they may serve me; this demand had been often made, and, though so reasonable, was refused.