﴿ وَإِن يَرَوْا۟ ءَايَةًۭ يُعْرِضُوا۟ وَيَقُولُوا۟ سِحْرٌۭ مُّسْتَمِرٌّۭ ﴾

“But if they [who reject all thought of the Last Hour] were to see a sign [of its approach], they would turn aside and say, “An ever-recurring delusion!” –”

And if they the disbelievers among Quraysh see a sign a miracle of the Prophet s they turn away and say this is ‘A powerful sorcery!’ mustamirr ‘powerful’ derives from al-mirra meaning ‘strength’; or it mustamirr means ‘incessant’.