He said, "I am your lord, the most high."
Translation endnotes
[79:24] Slave owners are called rab (lord, master) in Arabic (12:41). Pharaohs were claiming to be the lord/master of those humans whom they have subjugated. Enslaving humans and thus claiming to be their rab (lord, master) is polytheism, or associating one's ego with God as His partner See 12:39-42; 90:13; 4:25.