Indeed they, when it was said to them, "There is no deity (37:35)

﴿إِنَّهُمْ كَانُوا إِذَا قِيلَ لَهُمْ لَا إِلَٰهَ إِلَّا اللَّهُ يَسْتَكْبِرُونَ﴾
[ الصافات: 35]

37:35 Indeed they, when it was said to them, "There is no deity but Allah," were arrogant

Indeed, these idolaters, when it would be said to them in the world, “There is no deity worthy of worship except Allah” so that they could act upon its requirements and leave everything that contradicted it, they would reject answering the call to it and submitting to it out of arrogance from the truth and showing haughtiness to it.

Truly, when it was said to them: La ilaha ill-Allah "(none has the right to be worshipped but Allah)," they puffed themselves up with pride (i.e. denied it).

phonetic Transliteration

Innahum kanoo itha qeela lahum la ilaha illa Allahu yastakbiroona

Abdullah Yusuf Ali - Translation

For they, when they were told that there is no god except Allah, would puff themselves up with Pride,

Safi-ur-Rahman al-Mubarakpuri

Truly, when it was said to them: "La ilaha illallah," they puffed themselves up with pride.

Page 447 English transliteration