"Have you seen him who takes his own desire as his god?" (45:23) He is the polytheist who took his desire as a god; so he worshipped idols instead of Allah.
His saying: "And Allah has sent him astray knowingly, and has sealed his hearing," meaning he does not hear the guidance from Allah, i.e., the hearing of acceptance. "And his heart," meaning: and He sealed his heart; so he does not understand the guidance.
"And set a veil over his sight," so he does not see the guidance. "Then who will guide him after Allah?" meaning: no one. "Will you not then remember?"
Muhammad said: "Gishawah" (veil) is a covering, and from it comes the "ghashiyah" (cover) of a saddle, and one of them recited:
I accompanied you when my eye was covered with a veil, then when it cleared, I cut myself off, blaming it.
It is said: "Ghushawah" with the damma on the ghayn, and "ghashwah" with its fatha without an alif, and it has been recited with both.