וַיֹּ֣אמֶר פַּרְעֹ֔ה מִ֤י יְהוָה֙ אֲשֶׁ֣ר אֶשְׁמַ֣ע בְּקֹל֔וֹ לְשַׁלַּ֖ח אֶת־יִשְׂרָאֵ֑ל לֹ֤א יָדַ֙עְתִּי֙ אֶת־יְהוָ֔ה וְגַ֥ם אֶת־יִשְׂרָאֵ֖ל לֹ֥א אֲשַׁלֵּֽחַ׃
Firaun menjawab, “Siapakah Yang Mahakekal itu, sehingga aku harus mendengarkan perkataan-Nya untuk membiarkan Israel pergi? Aku tidak mengenal Yang Mahakekal, dan lagi pula aku tidak akan membiarkan Israel pergi.”
Rashbam
מי ה' אשר אשמע בקולו לשלח את ישראל?, They are my slaves in my country to perform slave labour there. What possible interest could this Hashem have in demanding that they serve Him instead?
Sforno
'לא ידעתי את ה; I have never heard of any Being which created something tangible out of an absolute nothing.
Or HaChaim
אשר אשמע בקולו, "that I should listen to His voice." Pharaoh challenged Moses regarding his G'd's great power. Surely the Jewish G'd was not so powerful that He could demand such obedience in a matter of such overriding importance! He added gratuitously: "to dismiss the Jewish people," meaning that however great His power it would surely not suffice to liberate the Jewish people. Pharaoh did not mean to concede that he did know of the Jewish G'd after all, but that the latter was not great enough to make such a demand; rather he said: 1) "I do not know of Him;" 2) even if I would be told that He does indeed exist this would not mean that He could demand the freeing of the Jewish people." The word גם refers to a hypothetical situation.