Surah Al-Anfal 8:31

وَإِذَا تُتْلَىٰ عَلَيْهِمْ ءَايَـٰتُنَا قَالُوا۟ قَدْ سَمِعْنَا لَوْ نَشَآءُ لَقُلْنَا مِثْلَ هَـٰذَآ ۙ إِنْ هَـٰذَآ إِلَّآ أَسَـٰطِيرُ ٱلْأَوَّلِينَ

And when Our verses are recited to them, they say, "We have heard. If we willed, we could say [something] like this. This is not but legends of the former peoples."

Translation: Saheeh International

Tafsir

And when Our verses namely the Qur’ān were being recited to them they said ‘We have already heard! If we wish we can speak the like of this — al-Nadr b. al-Hārith said this for he used to travel on trading business to al-Hīra where he would buy books containing the tales of the Persians and would recount these to the …

Excerpt from Tafsir al-Jalalayn, commentary on 8:31, via Quran.com. The reader has the full commentary and 9 more tafsirs.