The Quran

Preface

وَقالَ فِرعَونُ يا أَيُّهَا المَلَأُ ما عَلِمتُ لَكُم مِن إِلٰهٍ غَيري فَأَوقِد لي يا هامانُ عَلَى الطّينِ فَاجعَل لي صَرحًا لَعَلّي أَطَّلِعُ إِلىٰ إِلٰهِ موسىٰ وَإِنّي لَأَظُنُّهُ مِنَ الكاذِبينَ

Yusuf Ali

Pharaoh said: “O Chiefs! no god do I know for you¹ but myself: therefore, O Haman! light me a (kiln to bake bricks) out of clay, and build me a lofty² palace, that I may mount up to the god of Moses: but as far as I am concerned, I think (Moses) is a liar!”

Pharaoh claimed, himself, to be God-not only one god among many, but the only god: “I am your Lord Most High”: 79:24. At any rate he did not see why his people should worship any one but him.
I understand his speech to his minister Hainan to be sarcastic. But some Commentators have taken it very seriously and imagined that he actually thought of reaching the heavens by building lofty towers (Cf. 40:36).