Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(The roads of the heavens) the gates of heaven, (and may look upon) and may see (the God of Moses) whom he claims is in heaven and has sent him to me, (though verily I think him a liar) there is no God in heaven. But he got too busy with Moses and the tower was not built. (Thus was the evil that he did made fair-seeming unto Pharaoh, and he was debarred from the (right) way) and he was prevented from the Truth and guidance. (The plot of Pharaoh ended but in ruin) in disarray.
the routes of the heavens — the paths that lead to it, and look upon (read [indicative] fa-attali‘u as a supplement to ablughu, ‘I may reach’; or read [subjunctive] fa-attali‘a, as the response to ibni lī, ‘build for me’) the God of Moses; for I truly think that he, that is, Moses, is lying’, about his having a god other than me — Pharaoh said this in order to disguise [the truth]. And that is how the evil [nature] of his conduct was made to seem fair to Pharaoh, and [that is how] he was barred from the [right] way, the path to guidance (read sadda, ‘[that is how] he barred [others]’, or sudda, ‘[that is how] he was barred’). And Pharaoh’s guile ended only in ruin, loss.
Allah tells us of the arrogant and hostile defiance of Fir`awn and his rejection of Musa, when he commanded his minister Haman to build him a tower, i.e., a tall, high, strong fortress. He built it of bricks made from baked clay, as Allah says:
(Thus it was made fair seeming, in Fir`awn's eyes, the evil of his deeds, and he was hindered from the path;) means, this act of his building the tower, by means of which he wanted to deceive his people and make them think that he could prove that Musa was lying. Allah says:
وَمَا كَـيْدُ فِرْعَوْنَ إِلاَّ فِى تَبَابٍ
(and the plot of Fir`awn led to nothing but loss and destruction.) Ibn `Abbas and Mujahid said, "Meaning nothing but ruin.''
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
Pharaoh addresses these words to Hamim, his minister, interposing in the speech of the Believer in a way as though he has no regard for what he was saying. Therefore, he turns away from him arrogantly and says to Haman, "Build me a high tower so that I may climb it to see where the God of whom this Moses speaks, lives." (For explanation, see AI-Qasas: 38 and E.N.'s thereof).