Surah Al-Qamar 54:2

وَإِن يَرَوْا۟ ءَايَةً يُعْرِضُوا۟ وَيَقُولُوا۟ سِحْرٌ مُّسْتَمِرٌّ

And if they see a sign [i.e., miracle], they turn away and say, "Passing magic."

Translation: Saheeh International

Tafsir

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’.

Excerpt from Tafsir al-Jalalayn, commentary on 54:2, via Quran.com. The reader has the full commentary and 9 more tafsirs.