Sforno on Exodus 5:3/ספורנו על שמות ה׳:ג׳

1אלוקי העברים, concerning your statement that you never heard of such a Being, He is the G’d of the Hebrews, the ones who cleave to the religious teachings of עבר, the grandson of Shem, son of Noach. Concerning your statement that you will not release the Israelites, you would do well to listen to His instructions פן יפגענו, as He would punish both us and you.